Question

Three friends were eating chocolate chip cookies after school. Nacy ate four less than two times the amount of cookies that Kate ate. Avery ate two times the amount of cookies that Nancy ate. If the girls ate a total of 16 cookies, how many did each girl eat?

Answer 1

let the number of cookies that kate eats be ‘n’
kate : n
nacy : 2n-4
avery : 2(2n-4)

n + 2n-4 + 2(2n+4) = 18
7n - 12 = 16
7n = 28
n = 4

kate : 4
nacy : 2x4 - 4 = 4
avery : 2(2x4 - 4) =8