Question

A’s income is 125 percent of B’s income and A’s expenditure is 60 percent of B’s expenditure. If B saves 30 percent of his income, then how much percentage does A save of his own income?
1. 66.4 percent
2. 48.2 percent
3. 40.8 percent
4. 52.6 percent

Answer 1

Correct Answer - Option 1 : 66.4 percent

Given:

A's income = 125% of B's income

A's expenditure = 60% of B's expenditure

B save 30% of his income

Solution:

Let the income of B be 100x

Income of A = 125% of B's income

Income of A = (125/100) × 100x = 125x

Let the expenditure of B be 100y

 A's expenditure = (60/100) × 100y = 60y

∴ Saving of B = 100x - 100y

⇒ Saving of A = 125x - 60y

According to the question,

B saves 30% of his income

⇒ 100x - 100y = (30/100) × 100x

⇒ 100x - 100y = 30x

⇒ 100x - 30x = 100y

⇒ 70x = 100y

⇒ x/y = 10/7

⇒ Income of A = 125 × 10 = 1250

⇒ Saving of A = 125x - 60y

⇒ Saving of A = 125 × 10 - 60 × 7

⇒ Saving of A = 1250 - 420 = 830

According to the question,

A saves his income in percentage = (830/1250) × 100 = 66.4%

∴ A saves 66.4% of his own income.