There are 78 cookies in box C, 26 cookies in box B and 10 cookies in box A.
let the number of cookies in first box be represented mathematically as B-16
the number of cookies in second box be represented as B
the number of cookies in third box be represented as 3B
Since there are 124 cookies we can make an equation such that it becomes
B-16 +B +3B =124
Solving for B, we have
5B -16 =124
5B =124 +16
5B =130
B=130/5
B=26
Therefore Box A contains B-16 =26-16 =10 cookies
Box C contains 3B =3 X 26=78 cookies
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