Question

120. A man saves 20% of his income. If his
expenses be increased by 35%, by what per cent
his income is to be raised so that he can save 10%
of his income?
(A) 20%

(B) 30%

(C) 25% (D) 22%​

Answer 1

Step-by-step explanation:

Lets assume his income to be 100.

He saves 20%, so his expense is 80.

if his expense is increased by 35%, his new expense is 80 x 1.35 = 108

To save 10% on 108.. his income should be 108 / (1-10%)

= 108 / 0.9 = 120

Thus his income should increase by 20%

Answer 2

calculating savings of the person

explanation

let the total income of the man  be 100 units

so if he saves 20% of his income

i.e

100*20/100

=20

so after saving the 20 units from his income , now his total expenses is = 80 units

now as mentioned in question that the  expense is increased by 35%

so, 80*35/100

108

so now as in question it is asked that in order to save 10% on his expenses that is 108, what should be his income

so, 108/0.9

=120

thus his income should increase by 20%