Question

3 . 1 A number is increased by 10% and then decreased by 10%. The net change in the number is: (A) No increase or decrease (B) 2% decrease (C) 1% increase (D) 1% decrease​

Answer 1

Answer:

-In this question we are given that a number is first increased by 10% and then reduced by 10%. For this, let the number at the start be 100 and apply the directions given in question to get the result.

Complete step-by-step answer:

Let the number be 100

Number is increased by 10% = 100+10% of 100

=100+10

=110

Now, the resultant number is reduced by 10% =110-10% of 110

=110-11

=99

The number obtained is 99

Decrease in value = 100 – 99 = 1

Percentage decrease = 1100×100=1%

Hence the number is decreased by 1%.

Answer 2

(Option D is correct)

Explanation:

=> Let the number is 100

=> Increase 10% = 100 + 10 = 110

=> Decrease on 10% on 110

=> (10/100) x 110 = 11

=> Net amount = 110 - 11 = 99

=> So decrease = 100 - 99 = 1

=> Decrease of 1 out of 100

=> Percentage of decrease = 1%