The square of -8 is:

1. -16

2. 16

3. -64

4. 64

$-\sqrt{18 - \sqrt{11-7}}$ is equal to:

1. 4

2. -4

3. 2

4. 0

The smallest natural number which on multiplying with 48 gives a perfect square number is:

1. 12

2. 3

3. $\dfrac{1}{3}$

4. none of the above

The smallest natural number by which should 175 be divided to get a perfect square number is:

1. 5

2. 7

3. 15

4. none of the above