The LCM of two numbers is 72. Their ratio is 3 : 4. Find the sum of the numbers.

Correct option is D

Given:

LCM of two numbers = 72

Ratio of the numbers = 3 : 4

Formula Used:​​

LCM×HCF=Product of the numbers

Solution:​

Let the two numbers be 3x and 4x

Now, 

72 × HCF = 12x²​

HCF = $$\frac{12x^2}{72} = \frac{x^2}{6}$$​​

Since HCF must be an integer, x must be a multiple of 6. Let x = 6:

Then the numbers are:

3x = 18, 4x = 24

Sum of the numbers = 18 + 24 = 42