Question

the ratio of a's and b's income last year was 3 : 4. the ratio of their own incomes of last year and this year is 4 : 5 and 2 : 3 respectively. if the total sum of their present incomes is rs. 11310 then find the present income of b.

Answer 1

Let the current salary of a be x.

The current salary of b will be :

11310 - x

The ratio of the past salary and current salary of a and b is :

A

4 : 5

B

2 : 3

From the ratios :

The past salary of A and B are respectively :

4/5x and 2/3(11310 - x)

A = 4/5x

B = 7540 - 2/3x

The ratio of their past salaries is :

3 : 4

Hence :

(4/5x)/(7540 - 2/3x) = 3/4

4 × 4/5x = 3 × (7540 - 2/3x)

16/5x = 22620 - 2x

16x = 113100 - 10x

26x = 113100

x = 113100/26

x = 4350

b's current salary is thus :

11310 - 4350 = 6960

Rs 6960