Question

The income of a person is increased by 10% and then decreased by 10%. Find the change in his income.

• A. Increase by 1%
• B. Increase by 2%
• C. Decrease by 1%
• D. Decrease by 2%

Answer 1

The correct option is C Decrease by 1%

Given that,
The income of a person is increased by 10% and then it is decreased by 10%.

Now,
Let the persons original income be x.

When, there is a 10% increase in his income his new income will be,
= x + 10% of x
= 1.1x

Similarly, when there is a decrease in his new income his final income will be
= 1.1x - 10% of 1.1x
= 0.99x

Change in his income
= x - 0.99x
= 0.01x

Percentage change
= (change in his income / initial income) $\times$ 100
= [(0.01x /x )] $\times$ 100
= 1%

Hence, his income decreases by 1%.