The ratio of two numbers is 3 : 4 and their LCM is 120. The sum of numbers is = ?

Answer: Option A

Let the numbers are 3x and 4x
So HCF = x
∴ HCF × LCM = Product of numbers
⇒ x × 120 = 3x × 4x
⇒ x × 120 = 12x²
⇒ 120 = 12x
x = 10
∴ Numbers are 30 and 40
∴ Sum of two numbers = 30 + 40 = 70