Question

How can I solve this: Sandy decided to give one-fourth of her CDs to Jenn. Then she gives one-half of the remaining CDs to Bob. If she is left with 6 CDs,how many CDs did she have to begin with?

Answer 1

let the number she had be x

x - (1/4)x - (1/2)(3/4)x = 6
x - x/4 - 3x/8 = 6
times 8
8x - 2x - 3x = 48
3x = 48
x = 16
She had 16 CDs

check:
she had 16, gave 1/4 away
leaving her with 12
she gave 1/2 of those away, so she gave 6 of the remaining 12 away, leaving her with 6
-all checks out!