Liberal Arts Mathematics

#$&*

course Mth 152

9/15 12:15 am.

Liberal Arts MathematicsIf your solution to stated problem does not match the given solution, you should self-critique per instructions at

http://vhcc2.vhcc.edu/dsmith/geninfo/labrynth_created_fall_05/levl1_22/levl2_81/file3_259.htm

Your solution, attempt at solution. If you are unable to attempt a solution, give a phrase-by-phrase interpretation of the problem along with a statement of what you do or do not understand about it. This response should be given, based on the work you did in completing the assignment, before you look at the given solution.

004. Liberal Arts Mathematics

*********************************************

Question: `q001. Consider the statement 'If that group of six-year-olds doesn't have adult supervision, they won't act in an orderly manner.' Under which of the following circumstances would everyone have to agree that the statement is false?

The group does have supervision and they do act in an orderly manner.

The group doesn't have supervision and they don't act in an orderly manner.

The group doesn't have supervision and they do act in an orderly manner.

The group does have supervision and they don't act in an orderly manner.

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution: The only one I would think to choose would be the second option. ""The group doesn't have supervision"" and they don't act in an orderly manner."" I think this answer is best because if the group doesn't have anyone watching them and they are only 6 years old, chances are they are going to do whatever they want to do.

@&

You are making assumptions about 6-year-olds.

Your answer needs to be in terms of the given information only. Of course if that information isn't any good, neither is the conclusion, but logic makes no such distinction.

*@

confidence rating #$&*:: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Given Solution:

`aThe statement says that if the group doesn't have supervision, they will not act in an orderly manner. So if they don't have supervision and yet do act in an orderly manner the statement is contradicted.

If the group does have supervision, the statement cannot be contradicted because condition of the statement, that the group doesn't have supervision, does not hold. The statement has nothing to say about what happens if the group does have supervision.

Of course if the group doesn't have supervision and doesn't act in orderly manner this is completely consistent with the statement.

Therefore the only way to statement can be considered false is the group doesn't have supervision and does act in an overly manner.

Note that what we know, or think we know, about childrens' behavior has nothing at all to do with the logic of the situation. We could analyze the logic of a statement like 'If the Moon is made of green cheese then most six-year-olds prefer collard greens to chocolate ice cream'. Anything we know about the composition of the Moon or the tastes of children has nothing to do with the fact that the only way this statement could be shown false would be for the Moon to be made of green cheese and most six-year-olds to prefer the ice cream.

------------------------------------------------

Self-critique Rating:

OK

*********************************************

Question: `q002. List the different orders in which the letters a, b and c could be arranged (examples are 'acb' and 'cba'). Explain how you know that your list contains every possible order.

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

Well if I am arrranging the different orders od a, b, and c, there is only 2 ways with each letter without repetition.

So if I was to do a first, it would look like this: abc, acb.

Next is the letter b: bac, bca

Lastly, c: cab, cba

I know that these are correct because if you only have three letters and you have to start with the first one, the other two letters you switch around and there is not another way to do it.

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

`aThe only reliable way to get all possible orders is to have a system which we are sure the list every order without missing any.

Perhaps the simplest way to construct all possible orders is to list then alphabetically.

We start with abc. There is only one other order that starts with a, and it is obtained by switching the last two letters to get acb.

The next alphabetical order must start with b. The first possible listing starting with b must follow b with a, leaving c for last. The orders therefore bac. The only other order starting with b is bca.

The next order must start with c, which will be followed by a to give us cab. The next order is obtained by switching the last two letters to get cba.

This exhausts all possibilities for combinations of the three letters a, b and c. Our combinations are, in alphabetical order,

abc, acb, bac, bca, cab, cba.

------------------------------------------------

Self-critique Rating:

OK

*********************************************

Question: `q003. One collection consists of the letters a, c, d and f. Another collection consists of the letters a, b, d and g.

List the letters common to both collections.

List the letters which appear in at least one of the collections.

List the letters in the first half of the alphabet which do not appear in either of the collections.

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

confidence rating #$&*:

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The letters that are common to both collections are A and D. Only those two because both sets of numbers has those letters.

The letters that appear in at least on of the collections is: A, B, C, D, F, and G because those are the letters that are in both collections.

The letters in the first half of the alphabet are E, H, I, J, K, L, and M because 13 if half of the alphabet and if you write them out ABCDEFGHIJKLM and take away the 6 letters that were used in the question you end up with EHIJKLM

.............................................

Given Solution:

`aTo letters a and d each appear in both collections. No other letter does.

The letters a, c, d, and f appear in the first collection, so they all in at least one of the collections. In addition to letters b and g appear in the second collection. Therefore letters a, b, c, d, f and g all appear in at least one of the collections.

We consider the letters in the first half of the alphabet, in alphabetical order. a, b, c and d all appear in at least one of the collections, but the letter e does not. The letters f and g also appear in at least one of the collections, but none of the other letters of the alphabet do. The first half of the alphabet ends at m, so the list of letters in the first half of the alphabet which do not occur in at least one of the collections is e, h, i, j, k, l, m.

------------------------------------------------

Self-critique Rating:

@&

&#You did not answer the given question. You need to always at least explain what you do and do not understand about the question. A phrase-by-phrase analysis is generally required when you cannot otherwise answer a question.

&#

*@

OK

*********************************************

Question: `q004. Give the next element in each of the following patterns and explain how you obtained each:

2, 3, 5, 8, 12, ...

3, 6, 12, 24, ...

1, 3, 4, 7, 11, 18, ...

Your solution:

In the first set of numbers: 2, 3, 5, 8, and 12, the next number would be 17. My solution was this: 2+1 =3, 3+2 =5, 5+3 =8, 8+4= 12, and 12+5= 17. So it was like adding 1 then 2, then 3, then 4, then 5.

In the second set of numbers: 3, 6, 12, 24, the next number would be 48. My solution was this: 3+3=6, 6+6=12, 12+12=24, and 24+24= 48. It doubles the same number everytime.

In the third set of numbers: 1, 3, 4, 7, 11, 18, the next number would be 29. My solution to this was: 1+2= 3 then use that 3+4= 7, then use that 7+4= 11, then use that 11+18=29

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

`aThe pattern of the sequence 2, 3, 5, 8, 12, ... can be seen by subtracting each number from its successor. 3-2 = 1, 5-3 = 2, 8-5 = 3, 12-8 = 4. The sequence of differences is therefore 1, 2, 3, 4, ... . The next difference will be 5, indicating that the next number must be 12 + 5 = 17.

The pattern of the sequence 3, 6, 12, 24, ... can be discovered by dividing each number into its successor. We obtain 6/3 = 2, 12/6 = 2, 24/12 = 2. This shows us that we are doubling each number to get the next. It follows that the next number in the sequence will be the double of 24, or 48.

The pattern of the sequence 1, 3, 4, 7, 11, 18, ... is a little obvious. Starting with the third number in the sequence, each number is the sum of the two numbers proceeding. That is, 1 + 3 = 4, 3 + 4 = 7, 4 + 7 = 11, and 7 + 11 = 18. It follows that the next member should be 11 + 18 = 29.

------------------------------------------------

Self-critique Rating:

OK

*********************************************

Question: `q005. The number 18 can be 'broken down' into the product 9 * 2, which can then be broken down into the product 3 * 3 * 2, which cannot be broken down any further . Alternatively 18 could be broken down into 6 * 3, which can then be broken down into 2 * 3 * 3.

Show how the numbers 28 and 34 can be broken down until they can't be broken down any further.

Show that there at least two different ways to break down 28, but that when the breakdown is complete both ways end up giving you the same numbers.

Your solution:

If I am going to breakdown 28 two different wasy the it would be like this

7+4=32 which really equals 7*2*2. The other way would be 14*2=28 which really equals 7*2*2 because 14/7=2. So it would be 2*2*7.

The number 34 is a little easier because 34 is only divisible by 2 which means 34/2=17. 17 cannot be broken down any further now.

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Given Solution:

`aA good system is to begin by attempting to divide the smallest possible number into the given number. In the case of 34 we see that the number can be divided by 2 give 34 = 2 * 17. It is clear that the factor 2 cannot be further broken down, and is easy to see that 17 cannot be further broken down. So the complete breakdown of 34 is 2 * 17.

To breakdown 28 we can again divide by 2 to get 28 = 2 * 14. The number 2 cannot be further broken down, but 14 can be divided by 2 to give 14 = 2 * 7, which cannot be further broken down. Thus we have 28 = 2 * 2 * 7.

The number 28 could also the broken down initially into 4 * 7. The 4 can be further broken down into 2 * 2, so again we get 28 = 2 * 2 * 7.

It turns out that the breakdown of a given number always ends up with exactly same numbers, no matter what the initial breakdown.

------------------------------------------------

Self-critique Rating:

OK

*********************************************

Question: `q006. Give the average of the numbers in the following list: 3, 4, 6, 6, 7, 7, 9. By how much does each number differ from the average?

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

If I am finding the average then I have to add all the numbers up and divide them by how many numbers I have. So in this case I have 7 numbers. I will add 3 + 4 + 6 + 6 + 7 + 7 + 9 = 42. Now that I have that answer, I need to do 42/7 which equals 6.

The first number is 3 and it differs from the answer of 6 by 3.

The second number is 4 which differs from the answer 6 by 2.

The next to numbers and 6's which are equal to the answer.

The next two numbers are 7's which differ from the answer 6 by 1.

Last but not least, the last number us 9 which differs from the answer 6 by 3.

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

`aTo average least 7 numbers we add them in divide by 7. We get a total of 3 + 4 + 6 + 6 + 7 + 7 + 9 = 42, which we then divide by 7 to get the average 42 / 7 = 6.

We see that 3 differs from the average of 6 by 3, 4 differs from the average of 6 by 2, 6 differs from the average of 6 by 0, 7 differs from the average of 6 by 1, and 9 differs from the average of 6 by 3.

A common error is to write the entire sequence of calculations on one line, as 3 + 4 + 6 + 6 + 7 + 7 + 9 = 42 / 7 = 6. This is a really terrible habit. The = sign indicates equality, and if one thing is equal to another, and this other today third thing, then the first thing must be equal to the third thing. This would mean that 3 + 4 + 6 + 6 + 7 + 7 + 9 would have to be equal to 6. This is clearly not the case. It is a serious error to use the = sign for anything but equality, and it should certainly not be used to indicate a sequence of calculations.

------------------------------------------------

Self-critique Rating:

OK

*********************************************

Question: `q007. Which of the following list of numbers is more spread out, 7, 8, 10, 10, 11, 13 or 894, 897, 902, 908, 910, 912? On what basis did you justify your answer?

Your solution:

As I was writing these nunbers down I figured the best way possible to do this would be take the highest number in each setrand subtract it by the lowest. When I finished that, the first set of numbers 7-13 was a difference of only 6. The second set of numbers had a difference of 18. So the second set of numbers is my answer.

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

`aThe first set of numbers ranges from 7 to 13, a difference of only 6. The second set ranges from 894 to 912, a difference of 18. So it appears pretty clear that the second set has more variation the first.

We might also look at the spacing between numbers, which in the first set is 1, 2, 0, 1, 2 and in the second set is 3, 5, 6, 2, 2. The spacing in the second set is clearly greater than the spacing in the first.

There are other more sophisticated measures of the spread of a distribution of numbers, which you may encounter in your course.

------------------------------------------------

Self-critique Rating:

OK

*********************************************

Question: `q008. 12 is 9 more than 3 and also 4 times 3. We therefore say that 12 differs from 3 by 9, and that the ratio of 12 to 3 is 4.

What is the ratio of 36 to 4 and by how much does 36 differ from 4?

If 288 is in the same ratio to a certain number as 36 is to 4, what is that number?

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

The ratio of 36 to 4 is 9.

confidence rating #$&*: 1

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

`aJust as the ratio of 12 to 3 is 12 / 3 = 4, the ratio of 36 to 4 is 36 / 4 = 9. 36 differs from 4 by 36 - 4 = 32.

Since the ratio of 36 to 4 is 9, the number 288 will be in the same ratio to a number which is 1/9 as great, or 288 / 9 = 32.

Putting this another way, the question asks for a 'certain number', and 288 is in the same ratio to that number as 36 to 4. 36 is 9 times as great as 4, so 288 is 9 times as great as the desired number. The desired number is therefore 288/9 = 32.

Self-critique ( if necessary): I am not exactly sure what it means when it is saying that ""DIFFERS"" from a certain number. I understand the ratio from 36 to 4 is 9, but not anywhere beyond that???

------------------------------------------------

Self-critique Rating: 1

@&

12 differs from 3.

By how much?

12 - 3 is 9, so 12 differs from 3 by 9.

*@

*********************************************

Question: `q009. A triangle has sides 3, 4 and 5. Another triangle has the identical shape of the first but is larger. Its shorter sides are 12 and 16. What is the length of its longest side?

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

If the small triangle is 3, 4, and 5 the the numbers that are in the bigger triangle are 4 times those numbers. So it would be 3*4=12 then 4*4=16 then 5*4=20. So the longest side of the triangle would be 20.

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.............................................

Given Solution:

`a** You need to first see that that each side of the larger triangle is 4 times the length of the corresponding side of the smaller. This can be seen in many ways, one of the most reliable is to check out the short-side ratios, which are 12/3 = 4 and 16/4 = 4. Since we have a 4-to-1 ratio for each set of corresponding sides, the side of the larger triangle that corresponds to the side of length 5 is 4 * 5 = 20. **

Self-critique Rating:

OK

*********************************************

Question: `q010. List the different orders in which John, Mary and Sally can be lined up, from left to right, for a picture.

In how many orders can the three be lined up so that the two women are next to each other?

YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY

Your solution:

The different orders could only go four ways if we wanted Sally and Mary to be beside each other every time.

John, Mary, Sally

John, Sally, Mary

Mary, Sally, John

Sally, Mary, John.

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

*********************************************

Question: `q011. If John is next to Mary, Sally will be jealous. Sally is jealous. Does it logically follow that John is next to Mary? Explain.

Your solution:

In my answer, there are four different ways that the women would be beside each other. Each woman, Sally and Mary, is beside John the equal amount of time. Which means Sally needs to grow up and quit being jealous.

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

*********************************************

Question: `q012. By how much does each of the numbers 81, 85, 89, 83, 86, 86 differ from the average of the six numbers? The average is a whole number, and you should be able to figure out the number without using a calculator.

Explain how you got your solution.

Your solution:

I took 81, 85, 89, 83, 86, 86 and added them all up and got 510. The I divided 510 by 6 because there was 6 numbers from that set of numbers.

510/6= 85

81 differs from 85 by 4.

85 is equal to 85.

89 differs from 85 by 4.

83 differs from 85 by 2.

86 differs from 85 by 1.

confidence rating #$&*:: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

*********************************************

Question: `q013. You have blocks colored red, yellow, blue, orange and pink. I have blocks colored yellow, green, blue, purple, brown and white.

How many colors do you have?

How many colors do I have?

How many colors are there all together?

How many colors do we have in common?

How many colors do I have that you don't?

How many colors do you have that I don't?

If I had 9 colors and you had 12, and if there were a total of 18 colors present, then how many colors would I have that you don't, how many would you have that I don't, and how many would we have in common?

Your solution:

How many colors do you have? I have 5 colored blocks.

How many colors do I have? You have 6 colored blocks.

How many colors are there all together? We have 11 colors all together

How many colors do we have in common? We have 2 colors in common.

How many colors do I have that you don't? You have 4 colored blocks that I do not have.

I have 3 colored blocks that you do not have.

If I had 9 colors and you had 12, and if there were a total of 18 colors present, then how many colors would I have that you don't, how many would you have that I don't, and how many would we have in common?

I am not sure I understand this one though because if I had 12 colors and you had 9, that would equal 21. So three colors would be missing which could possibly mean I add those 3 to the other 3 since 12-9=3. So could it be that I have 6 more than you have and we both have 9 same colors???

confidence rating #$&*: 3

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

*********************************************

Question: `q014. The number 18 can be 'broken down' into the product 9 * 2, which can then be broken down into the product 3 * 3 * 2, which cannot be broken down any further . Alternatively 18 could be broken down into 6 * 3, which can then be broken down into 2 * 3 * 3.

In how many different ways could we completely break down the number 72?

If we put the numbers in the final breakdown in order from least to greatest, do all possible breakdowns lead to the same result, or is there more than one possible final result?

Your solution:

My solution to this one would be:

72 which I broke down into 9 and 8.

9= 3*3

8= 4*2 which really equals 8= *2*2*2 ???

@&

Good.

So 72 = 3 * 3 * 2 * 2 * 2.

*@

confidence rating #$&*: 2

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

*********************************************

Question: `q015. Of the numbers 1240, 1270, 1320 and 1500, which do you think differs the most from the average of the four numbers? Answer as best you can without doing any calculations, and give your reasoning.

Your solution:

If I have to choose a number that would be furthest away from the average of those numbers, it would probably be 1500. My reasoning behind this is that the other 3 numbers are pretty close in sequence whereas 1500 is pretty far off so the average would have to be less than 1400.

confidence rating #$&*: 3 "

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Self-critique (if necessary):

------------------------------------------------

Self-critique rating:

&#Your work looks good. See my notes. Let me know if you have any questions. &#