Question

The incomes of A and B are in the ratio 9:7 and their expenditures are in the ratio of 4: 3. If each saves Rs 200, find their income (x = 200 y = 400) Rs 1800, Rs 1400

Answer 1

Let their salaries be 9x and 7x

let their expenditure be 4y and 3y

so,

ATQ

9x-4y=200—(1)

7x-3y=200—(2)

so,

from (1)

x=(200+4y)/9—(3)

put x in (2)

7[(200+4y)/9]-3y=200

(1400+28y)/9-3y=200

(1400+28y-27y)/9=200

y+1400=1800

y=400

now put y in (3)

x=(200+4×400)/9

x=(200+1600)/9

x=1800/9

x=200

so,

salary of first person=9×200=1800 rs

salary of second person=7×200=1400 rs