SOLUTION: The ratio of Devi’s marbles to Eddie’s marbles was 2:5. After Devi gave away 8 marbles and Eddie gave away 40 marbles, the ratio of Devi’s marbles to Eddie marbles became

Algebra ->  Percentage-and-ratio-word-problems -> SOLUTION: The ratio of Devi’s marbles to Eddie’s marbles was 2:5. After Devi gave away 8 marbles and Eddie gave away 40 marbles, the ratio of Devi’s marbles to Eddie marbles became       Log On


   



Question 1184096: The ratio of Devi’s marbles to Eddie’s marbles was 2:5. After Devi
gave away 8 marbles and Eddie gave away 40 marbles, the ratio of
Devi’s marbles to Eddie marbles became 1:2. How many marbles
did Devi have at first?

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
The ratio of Devi’s marbles to Eddie’s marbles was 2:5.
After Devi gave away 8 marbles and Eddie gave away 40 marbles, the ratio of
Devi’s marbles to Eddie marbles became 1:2.
How many marbles did Devi have at first?
:
let x = the multiplier
then
2x = D's marbles originally
and
5x = E's marbles originally
:
"After Devi gave away 8 marbles and Eddie gave away 40 marbles, the ratio of
Devi’s marbles to Eddie marbles became 1:2. "
%282x-8%29%2F%285x-40%29 = %281x%29%2F%282x%29
cancel the second fraction's x's
%282x-8%29%2F%285x-40%29 = 1%2F2
cross multiply
5x - 40 = 2(2x-8)
5x - 40 = 4x - 16
5x - 4x = -16 + 40
x = 24 is the multiplier
therefore
2*24 = 48 marbles D had originally
:
Check solution with substitution in the first equation
%2848-8%29%2F%28120-40%29 = %2840%29%2F%2880%29