Question

The monthly income of A and B are in the ratio of 9:7 and those of B and C are in the ratio of 7:5 if 10% A's icome exceed 16% of c's income by ₹120 find monthly income of A,B and C​

Answer 1

Question :

The monthly income of A and B are in the ratio of 9:7 and those of B and C are in the ratio of 7:5 if 10% A's income exceed 16% of c's income by ₹120 find monthly income of A,B and C​.

Given :

The monthly income of A ; B = 9 : 7

The monthly income of B : C = 7 : 5

10% of A exceeds 16% of C by 120 rupees

To find :

find A , B and C

Solution :

Its given 10 % A exceeds

A/B = 9/7..... (1)

B/C = 7/5..... (2)

From (1)

A/B = 9/7

1/B = 9/7A

  B = 7A/9,....(3)

Now ,substitute the value of B in (2)

  B/C = 7/5

  1/C = 7/5 x 1/B

  C  = 5/7 x B

  C  =  5/7 x  7/9

  C  = 5A/9 .... (4)

Its noted that,

10%A  = 16%C + 120

10%A - 16%C  = 120

Substitute (4) in the following equation,

10/100 A - 16/100 x 5/9 A = 120

10/100 A - 2/45 A = 120

90A - 40A / 900 = 120

50A = 120 X 900

A = 2160

Now substitute value of A in (3)

B = 7/9 A

B = 7/9 x 2160

B = 15120 / 9

B = 1680

Now substitute the value of A in (4)

C = 5/9 A

C = 5/9 x 2160

C = 10800 / 9

C = 1200

Values :

A = 2160

B = 1680

C = 1200