The ratio of M, N and S is 2 : 7 : 9 respectively. If their sum is 360, then what is the difference between M and S?

Correct option is C

Given:

The ratio of M : N : S is 2 : 7 : 9
Sum of M + N + S = 360

Solution:
Let the common multiplying factor be x.

So,
M = 2x
N = 7x
S = 9x

Now,
M + N + S = 2x + 7x + 9x = 18x
Given 18x = 360
=> x = 360 ÷ 18 = 20

Now calculate M and S:
M = 2 × 20 = 40
S = 9 × 20 = 180

Difference between M and S = 180 - 40 = 140

Final Answer: (C) 140