Question:The incomes of `A, B, C` are in the ratio of `7 : 9 : 12` and their spendings ate in the ratio of `8 : 9 : 15`. If `A` saves `1/4`th of his income, then the savings of `A, B, C` are in the ratio of :
+ ExplanationLet their incomes be `7x, 9x` and `12x` and their spendings be
`8y, 9y` and `15y`.
Theb, their saving are `(7x - 8y), (9x - 9y) & (12x - 15y)`.
Now, `7x - 8y = (7x)/4` or
`21x = 32y` or `x/y = (32)/(21)`.
`:. (7x - 8y)/(9x - 9y) =(7 (x/y) - 8)/(9 (x/y) - 9)`
`= (7 xx ((32)/(21)) - 8)/(9 xx ((32)/(21)) - 9)`
`= 8/3 xx 7/(33)`
`= (56)/(99)`.
`(9x - 9y)/(12x - 15y) = (9 (x/y) - 9)/(12 (x/y) - 15)`
`= (9 xx (32)/(21) - 9)/(12 xx (32)/(21) - 15)`
`= (33)/(23)`
`= (99)/(69)`.
`:.` Ratio of savings `= 56 : 99 : 69`.
