The ratio of Mario's money to Luigi's money was 9:4 before Mario went to the store. After Mario spent $84 on jackets, the ratio became 1:2. How much money did Mario have at first?
M --> Mario's
L--> Luigi's
According to question:
\( {M \over 4} = {9 \over 4}\)
4M = 9L ---- eq1(1)
Again \( {M - 84 \over L } = {1 \over 2}\)
2M - 168 = L ---- equation (2)
Putting the value of in equation (1)
4M = 9(2M - 168)
4M = 18M - 1512
14M = 1512
M = \({1512\over14 } = 108\)
M = 108
the ratio have at first money is $108