Aaron and Ben have a total of 976 trading cards. Ben has 7 times as many cards as Aaron. How many cards should Ben give Aaron so that Aaron will have 3 times as many cards as Ben?

Answer 1

right now:
x + 7x = 976
x= 122

Aaron has 122 cards and Ben has 854.

after the give-away of k cards:
ben has 854-k
Aaron has 122+k

Aaron has 3 times as many as Ben
122+k = 3(854 - k)
122+k = 2562 - 3k
4k = 2440
k = 610

check:
after the exchange
Ben has 854-610 = 244
Aaron has 122 + 610 = 732
which is 3(244)