Question

A number increased by 20% gives 42. The number is
(a) 35
(b) 28
(c) 36
(d) 30

Answer 1

(a) 35
Let the required number be x.
Then, x + 20% of x = 42
⇒ $x+\frac{20x}{100}=42$
⇒$x+\frac{x}{5}=42$
⇒ $\frac{5x+x}{5}=42$ [∵ LCM of 1 and 5 = 5]
⇒ $\frac{6x}{5}=42$
∴$x=42\times \frac{5}{6}=35$
Hence, the required number is $35$.