# Square and Cube Roots Quiz Set 015

### Question 1

How many 2 digit numbers are their whose squares end in 8?

A

0.

B

11.

C

10.

D

5.

Soln.
Ans: a

It is not possible for the square of any number to end in 2, 3, 7 or 8. Hence the answer is 0.

### Question 2

One-fourth of the cube-root of which number is 0.4?

A

4.096.

B

4.024.

C

4.256.

D

4.128.

Soln.
Ans: a

Let the number be n. So \${1/4} × √^3n\$ = 0.4, which gives \$√^3n\$ = 4 × 0.4 = 1.6. so n = \$1.6^3\$ = 4.096.

### Question 3

If x = 0.3193, then what is the value of \$11x + √{16x^2 - 8x + 1}\$?

A

3.24.

B

0.324.

C

32.4.

D

3.16.

Soln.
Ans: a

By inspection, \$11x + √{16x^2 - 8x + 1}\$ is same as \$11x + √{({1 - 4x})^2}\$, which is same as 11x + (1 - 4x) = 1 + 7x = 3.24.

### Question 4

How many 2 digit numbers are their whose squares end in 8?

A

0.

B

16.

C

9.

D

1.

Soln.
Ans: a

It is not possible for the square of any number to end in 2, 3, 7 or 8. Hence the answer is 0.

### Question 5

What is √0.0009?

A

0.03.

B

0.9.

C

0.3.

D

0.81.

Soln.
Ans: a

We can see that 0.03 × 0.03 = 0.0009, so square root is 0.03.

Updated on 2020-02-07. Published on: 2016-04-20

Posted by Parveen(Hoven),
Aptitude Trainer