The smallest possible number of wings that could have been in the
bucket is 119.
Here are three different ways that were used to get that
answer. Do any of them look like your solution? Did you learn anything
from these solutions?
Solution 1:
I made a chart of numbers and as I checked each number to see if it
worked I marked off the numbers that didn't work. I started with 1 but
that was kind of silly because 1, 2, 3, 4, 5, and 6 can't be divided
by 7 evenly. So, I quickly marked those off my chart.
7 works for some of the numbers:
7/2 = 3, remainder 1
but 7/3 = 2, remainder 1 and so that isn't right.
I kept going, checking each number until I got one part that didn't
work. As I was working, I figured out that the number would have to be
odd because none of the even numbers could be divided by 2 but still
have a remainder of 1. Once I figured that out I crossed out all of the
even numbers. Then I started thinking that if 7 went into the number
with no remainder, the number would have to be a multiple of 7. I
crossed out all of the numbers on my chart that weren't multiples of
7.
That made my work a little easier. When I finally got to 119, it
worked for all of the numbers!
119/2 = 59, remainder 1
119/3 = 39, remainder 2
119/4 = 29, remainder 3
119/5 = 23, remainder 5
119/6 = 19, remainder 6
119/7 = 17, remainder 0
Solution 2:
Since the problem says that if you take the wings out seven at a
time there won't be any wings left over, I know that the number of
wings will be a multiple of 7. So, I started thinking of the multiples
of 7:
7 works for 2 because 7/2 is 3 with a remainder of 1 but it doesn't
work for 3 because 7/3 is 2 with a remainder of 1.
Next, I tried 14 but it didn't work for 2 because 14/2 is 7 with no
remainder.
I tried 21 but it didn't work for 3 because 21/3 is 7 with no
remainder.
I tried 28 but it didn't work for 2 because 28/2 is 14 with no
remainder.
I tried 35 but it didn't work for 5 because 35/5 is 7 with no
remainder.
I tried 42 but it didn't work for 2 because 42/2 is 21 with no
remainder.
I tried 49 but it didn't work for 3 because 49/3 is 16 with 1
remainder.
I tried 56 but it didn't work for 2 because 56/2 is 18 with no
remainder.
I tried 63 but it didn't work for 3 because 63/3 is 21 with no
remainder.
I tried 70 but it didn't work for 2 because 70/2 is 35 with no
remainder.
I tried 77 but it didn't work for 2 because 77/4 is 19 with 1
remainder.
I tried 84 but it didn't work for 2 because 84/2 is 42 with no
remainder.
I tried 91 but it didn't work for 2 because 91/3 is 30 with 1
remainder.
I tried 98 but it didn't work for 2 because 98/2 is 49 with no
remainder.
I tried 105 but it didn't work for 5 because 105/5 is 21 with no
remainder.
I tried 112 but it didn't work for 2 because 112/2 is 56 with no
remainder.
I tried 119 and it worked! Whew, I found the number. It's 119.
Solution 3:
Let N be the number of wings.
Since there was 1 left when dividing by 2, N must be one less than a
multiple of 2.
Since there were 2 left when dividing by 3, N must be one less than a
multiple of 3.
Since there were 3 left when dividing by 4, N must be one less than a
multiple of 4.
Since there were 4 left when dividing by 5, N must be one less than a
multiple of 5.
Since there were 5 left when dividing by 6, N must be one less than a
multiple of 6.
Therefore we can say N is one less than a multiple of 60. And we
know N is a multiple of 7.
60 - 1 = 59, not a multiple of 7.
120 - 1 = 119, Yes! A multiple of 7.