Question

Two years ago, when the number of students of a school was increased by 25%, it became 500. Last year, again the number was increased by 20%. How many new students were enrolled in two years​

Answer 1

200 new students

Explanation:

Let the number of students enrolled 2 years ago be X

Then last year because of the increase of 25% it became 500

Increase of 25% = 0.25X

Total student population after increase = X + 0.25X = 1.25X

We know that after the first increase, the number became 500

So 1.25X = 500, X = 500/1.25 = 400 (number 2 years ago)

Last year it increased from 500 by 20%. So current number of students = 500 x 1.20 = 600

Difference between current number and number two years ago gives the number of new students as 600-400 = 200