What is the smallest perfect square number which is completely divisible by 4, 6, 9, 12 and 15?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 900.
Prime factorization
Prime factorization of 4 = 22
Prime factorization of 6 = 2 × 3
Prime factorization of 9 = 32
Prime factorization of 12 = 22 × 3
Prime factorization of 15 = 3 × 5
LCM of 4, 6, 9, 12 and 15 = 180
Now, the smallest perfect square number will be a multiple of 180.
⇒ 180k (put k = 5)
⇒ 180 × 5 = 900