If 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.

 

008.  `Query 8

 

 

Question:  `q (previously 1.3.6)  There are a number of  9 and 11 yr old horses in the barn and the sum of their ages is 122.  How many 9- and 11-year-old horses are there?

 

Your solution: 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Confidence Assessment:

Given Solution: 

`a** If there was one 11-year-old horse the sum of the remaining ages would have to be 122 - 11 = 111, which isn't divisible by 9.

 

If there were two 11-year-old horses the sum of the remaining ages would have to be 122 - 2 * 11 = 100, which isn't divisible by 9.

 

If there were three 11-year-old horses the sum of the remaining ages would have to be 122 - 3 * 11 = 89, which isn't divisible by 9.

 

If there were four 11-year-old horses the sum of the remaining ages would have to be 122 - 4 * 11 = 78, which isn't divisible by 9.

 

If there were five 11-year-old horses the sum of the remaining ages would have to be 122 - 5 * 11 = 67, which isn't divisible by 9.

 

The pattern is

 

122 - 11 = 111, not divisible by 9

122 - 2 * 11 = 100, not divisible by 9

122 - 3 * 11 = 89, not divisible by 9

122 - 4 * 11 = 78, not divisible by 9

122 - 5 * 11 = 67, not divisible by 9

122 - 6 * 11 = 56, not divisible by 9

122 - 7 * 11 = 45, which is finally divisible by 9.

 

Since 45 / 9 = 5, we have 5 horses age 9 and 7 horses age 11.  **

 

 

 

Self-critique (if necessary):

 

 

 

 

 

 

 

 

 

 

Self-critique Rating:

Question:  `qQuery 1.3.32 (previously 1.3.10) divide clock into segments each with same total

 

 

Your solution: 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Confidence Assessment:

Given Solution: 

`a** The total of all numbers on the clock is 78.  So the numbers in the three sections have to each add up to 1/3 * 78 = 26.

 

This works if we can divide the clock into sections including 11, 12, 1, 2;     3, 4, 9, 10;            5, 6, 7, 8.    The numbers in each section add up to 26.

 

To divide the clock into such sections the lines would be horizontal, the first from just beneath 11 to just beneath 2 and the second from just above 5 to just above 8. Horizontal lines are the trick. 

 

You might have to draw this to see how it works.  **

 

 

Self-critique (if necessary):

 

 

 

 

 

 

 

 

 

 

Self-critique Rating:

Question:  `qQuery  1.3.48 (previously 1.3.30)  Frog in well, 4 ft jump, 3 ft back.

 

Your solution: 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Confidence Assessment:

Given Solution: 

`a** COMMON ERROR:  20 days

 

CORRECTION: 

 

The frog reaches the 20-foot mark before 20 days.

 

On the first day the frog jumps to 4 ft then slides back to 1 ft. 

On the second day the frog therefore jumps to 5 ft before sliding back to 2 ft. 

On the third day the frog jumps to 6 ft, on the fourth to 7 ft., etc. 

Continuing the pattern, on the 17th day jumps to 20 feet and hops away. 

 

The maximum height is always 3 feet more than the number of the day, and when max height is the top of the well the frog will go on its way.  **

 

 

Self-critique (if necessary):

 

 

 

 

 

 

 

 

 

 

Self-critique Rating:

Question:  `qQuery  1.3.73 (previously 1.3.48)  How many ways to pay 15 cents?

 

 

Your solution: 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Confidence Assessment:

Given Solution: 

`a** To illustrate one possible reasoning process, you can reason this out in such a way as to be completely sure as follows:

 

The number of pennies must be 0, 5, 10 or 15.

 

If you don't use any pennies you have to use a dime and a nickle. 

If you use exactly 5 pennies then the other 10 cents comes from either a dime or two nickles.

If you use exactly 10 pennies you have to use a nickle.

Or you can use 15 pennies.

 

Listing these ways:

 

1 dime, 1 nickel

1 dime, 5 pennies

2 nickels, 5 pennies

3 nickels

15 pennies

1 nickel  10 pennies

 

**

 

 

 

Self-critique (if necessary):

 

 

 

 

 

 

 

 

 

 

Self-critique Rating:

Question:  `qQuery  1.3.68 (previously 1.3.52)  Given 8 coins, how do you find the unbalanced one in 3 weighings

 

Your solution: 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Confidence Assessment:

Given Solution: 

`a** Divide the coins into two piles of 4.  One pile will tip the balance. 

Divide that pile into piles of 2.    One pile will tip the balance. 

Weigh the 2 remaining coins.  You'll be able to see which coin is heavier. **