Question

The least common multiple of 2, 5, 6, and 9 is A. 60. B. 45. C. 90. D. 180.

Answer 1

The least common multiple between those following numbers is C. 90.

Answer 2

Lets do it by finding the L.C.M
 
         
 (2, 5, 6, 9)
divide the terms by two and leave those which are not divisible

2  (1,5,6,9)

divide the terms by 3 and leave those which are not divisible

2 x 3  (1,5,2,3)

divide the terms by 3 again and leave those which are not divisible

2 x 3 x 3  (1,5,2,1)

divide the terms by two and leave those which are not divisible


2 x 3 x 3 x 2 (1,5,1,1)

divide the terms by five and leave those which are not divisible

2 x 3 x 3 x 2 x 5 (1,1,1,1)
So the L.C.M is :

2 x 3 x 3 x 2 x 5=180
so correct option is D 
hope it helps