Problema Solution
Troy decided to give away some of his compact disc. He gave one fourth of his CDs to Todd. Then he gave half of the remaining CDs to Ryan. If he is left with six CDs, how many did he have in the beginning.
Answer provided by our tutors
let 'x' be the number of CDs Troy had
he gave one fourth of his CDs to Todd: x/4
he gave half of the remaining CDs to Ryan: (x - x/4)/2
he is left with 6 CDs: x - (x/4 + (x - x/4)/2) = 6
by solving the equation
x - (x/4 + (x - x/4)/2) = 6
we find
x = 16 CDs
in the beginning Troy had 16 CDs.