Correct Answer - Option 1 : 25

**Given:**

Numbers are in the ratio 5 : 6.

L.C.M of number = 150

**Calculation:**

Let the number be 5x and 6x respectively.

As L.C.M of numbers = Common factor

⇒ 150 = x × 5 × 6

⇒ x = 150/30 = 5

⇒ The Smallest number = 5x = 25

**∴ The smallest number is 25.**

In arithmetic and number theory, the least common multiple, the lowest common multiple, or smallest common multiple of two integers a and b, usually denoted by LCM(a, b), is the smallest positive integer that is divisible by both a and b.