The incomes of A and B are in the ratio 4 : 5 and their expenditure are in the ratio 5 : 4. If A saves Rs. 6000 and B saves Rs. 12000, then what will be the income of A ?

Rs. 16000

                      A  :  B 

Income           4  :  5

Expenditure     5  :  4 

_____________________

Savings =  -6000    -12000              (Income - Expenditure)

ATQ,

⇒ $\frac{4R - 6000}{5R- 12000} = \frac{5}{4}$

Using cross - multiplication method, 

⇒ 25R - 16R = (-6000 x 4) - (-12000 x 5)

⇒       9R       = 36000

⇒         R       = 4000

Income of A = 4 x 4000 = Rs. 16000