M is inversely proportional to N. If M is 18, then N is 10. If N = 9, then what is the value of M?

Correct option is D

Given:

M is inversely proportional to N

When M = 18, N = 10

Find M when N = 9

Concept Used:

In inverse proportion, the product of the two variables remains constant:

M × N = constant

Solution:

From the first condition:

18 × 10 = 180

Now using this constant for the new value:

M × 9 = 180

M = $$\frac{180}{9}$$​ = 20