Question

The ratio of the income of two persons is 9:7,and the ratio of their expenditure is 4:3.each of them saves rs 200 yearly.find their yearly income ?

Answer 1

Let the income of person A and his expenditure be= 9x and 4y
Similarly, let the income and expenditure of person B be =7x and 3y respectively
Then,
9x-4y=200
7x-3y=200
Subtracting the equations,
9x-7x-4y+3y=0
So,2x=y
Put this value in both the equations.
9x-4y=200
9x-4(2x)=200
X=rs200
So,9x=200*9=rs1800
And 7x=200*7=rs1400
So income of the both of them are rs1800 and rs1400 respectively