Question

25% of a number is 15 Less than 30% of the number. Then 20% of the number is

Answer 1

Solution:-

Let the number be 'x'
So, according to the question.

25x/100 + 15 = 30x/100

Taking L.C.M. and solving it, we get.
⇒ (25x + 1500)/100 = 30x/100

⇒ After cross multiplying,
⇒ 3000x = 2500x + 150000
⇒ 3000x - 2500x = 150000
⇒ 500x = 150000
⇒ x = 300
20 % of x
20 % of 300
⇒ (20*300)/00
= 60
So, 20 % of the number is 60.

Let us cross check our answer.

25 % of a number is 15 less than 30 % of the number.
25 % 300 + 15 = 30 % of 300
75 + 15 = 90
90 = 90

L.H.S. = R.H.S.
Hence proved.

Answer 2

Solution - 

Let us assume, x is the number,

Given, 

25% of x = 30%x - 15

25/100 * x = 30/100 * x - 15

25x/100 = 30x/100 - 15

25x = 30x - 1500

5x = 1500

x = 300

The number is 300.

Therefore, 20% of the number = 20% of 300 = 20/100 * 300 = 60.