The least perfect square, which is divisible by each of 21, 36 and 66 is

Answer: Option A

Explanation:

as .4 * .4 = 0.16

Answer: Option B

Explanation:

$$\begin{aligned} => \sqrt{81} + \sqrt{0.81} = 10.09 - X \end{aligned}$$

$$\begin{aligned} => 9 + 0.9 = 10.09 - X \end{aligned}$$

$$\begin{aligned} => X = 10.09 - 9.9 = 0.19 \end{aligned}$$

Answer: Option B

Answer: Option C

Answer: Option D

Explanation:

L.C.M. of 21, 36, 66 = 2772

Now, 2772 = 2 x 2 x 3 x 3 x 7 x 11

To make it a perfect square, it must be multiplied by 7 x 11.

So, required number = 2 x 2 x 3 x 3 x 7 x 7 x 11 x 11 = 213444