Question

The ratio of the monthly incomes of a and b are in the ratio 4:3.the ratio of the monthly expenditure is 5:4.if a saves one fourth of his monthly income .find the ratio of their monthly savings

Answer 1

A’s & B’s , income ratio= 3:4 ie, their income is 3x & 4x

Expenditure ratio = 4:5, ie, their expenditure = 4y & 5y..

Now, since we need to calculate the ratio of their differences ie, (3x-4y) : (4x-5y)

For this it impiles that x>y to make the savings positive.

If we try to put all the ratio’s one by one

From ( 9:10) We get x:y = 5:6 ( so it contradicts the condition of saving is to be positive).

From (3:4) We get y=0( which is not possible because expenditure can’t be 0).

From ( 13:20) We get x:y = 15:8 ( so it satisfies the condition of saving is to be positive).

From (4:5) We get x=0( which is not possible because Income can’t be 0).

so from the above deduction 13:20 is the only ratio.