Percentages L1

In a certain year, a school had 60% boys and 40% girls as students. In the next five years the number of boys decreased by 10% and the number of girls increased by 10%. What is the change in total roll strength of the school in the five years?

  1. 3% increase
  2. 2% decrease
  3. No change
  4. 5% decrease

Answer

Let there are 100 students in a school.

Number of Boys = 60% of 100 = 60

Number of Girls = 40% of 100 = 40

After 5 years, the number of boys decreased by 10%.

Number of boys after 5 years = 60 - (10% of 60) = 54

After 5 years, the number of girls increased by 10%.

Number of girls after 5 years = 40 + (10% of 40) = 44

Total students after 5 years = 54 + 44 = 98.

Percentage change = (100-98)/100 = 2% decrease

The correct option is B.