Subject: General Aptitude · Chapter: Square Roots and Cube Roots · Exam: · Marks: · Difficulty:
The least perfect square, which is divisible by each of 21, 36 and 66, is
(a)213444
(b)214344
(c)214434
(d)231444
Answer
Answer (as printed): A
Explanation
L.C.M. of 21, 36, 66 $$\begin{aligned} & =2772 . \text { Now, } 2772 \\ & =2 \times 2 \times 3 \times 3 \times 7 \times 11 . \end{aligned}$$ To make it a perfect square, it must be multiplied by $7 \times 11$. So, required number $=2^{2} \times 3^{2} \times 7^{2} \times 11^{2}=213444$.
Explanation as extracted from the printed page; notation may be imperfect.