SOLUTION: Carlos had a bag of gum drops. He gave 1/4 of them to Monica, then gave half of what was left to Michael, then gave 1/6 of what was left to Ingrid. He then had 20 gumdrops left.

Algebra ->  Algebra  -> Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: Carlos had a bag of gum drops. He gave 1/4 of them to Monica, then gave half of what was left to Michael, then gave 1/6 of what was left to Ingrid. He then had 20 gumdrops left.       Log On

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Question 162348: Carlos had a bag of gum drops. He gave 1/4 of them to Monica, then gave half of what was left to Michael, then gave 1/6 of what was left to Ingrid. He then had 20 gumdrops left. How many did he have originally?
I wasn't sure what topic this would go under, so i just clicked one that said fractions. I was thinking that i would try to work backward, but i just don't understand how.
Answer by scott8148(5880) About Me  (Show Source):
You can put this solution on YOUR website!
let x=gumdrops

"He gave 1/4 of them to Monica" __ he kept 3/4 __ so 3x/4

"then gave half of what was left to Michael" __ he kept 1/2 __ 1/2 of 3x/4 is 3x/8

"then gave 1/6 of what was left to Ingrid" __ he kept 5/6 __ 5/6 of 3x/8 is 15x/48

"He then had 20 gumdrops left" __ 20=15x/48 __ 960=15x __ 64=x