The ratio to two number is 3 : 4. If the sum of these two numbers is 70, then what is their LCM?

Correct option is A

Given: The ratio to two number is 3 : 4. If the sum of these two numbers is 70.

Solution:

Let the numbers be 3x and 4x. Sum = 3x + 4x = 70.
3x + 4x = 70
=> 7x = 70
=> x = 10
The numbers are 30 and 40.
LCM of 30 and 40 = 120