Question

the sum of two numbers is 84 their ratio is 3:4 know the number

Answer 1

Let the no. be x
3x
4x
3x+4x=84
7x=84
x=84/7
x=12

Answer 2

Answer:

Let the numbers be 3x and 4x.

The factors of 3x are 3*x

The factors of 4x are 4*x

Its not important if x can be broken further as both the terms have x common.

So LCM= 3*4*x=12x

Given,

12x=84

=> x=7

Therefore the numbers are 21 and 28

The greater number is 28