When 21 is added to 30 % of a number, it gives the number itself. Find the number.
Answer:
30
- Let us assume the number to be x.
30 % of x = x ×
=30 100 30x 100 - If we look at the question carefully, we will notice that the number(x) is equal to the sum of 21 and 30 % of x.
So, it can be written as:
x = 21 +30x 100
⇒ x =21 × 100 + 30x 100
⇒ x =2100 + 30x 100
By cross multiplying both the sides
100 x = 2100 + 30x
⇒ 100 x - 30x = 2100
⇒ 70x = 2100
⇒ x =2100 70
⇒ x = 30 - Therefore, the number is 30.