Square and Cube Root- Aptitude Questions and Answers

View in English View in Hindi

What is the smallest number by which 3087 must be divided so that the quotient is a perfect cube?

A)

3


B)

21


C)

7


D)

9



Correct Answer :

9


Explanation :

Factors of 3087
3087 = 3 × 3 × 7 × 7 × 7 = 32 × 73

here only 3 is not in the cube.

Therefore 3 is the only number that is multiplied to make it a perfect cube.
And divide it by 3 × 3 which is 9 to make it a perfect cube.

Post comment
Cancel
Thanks for your comment.!
Write a comment(Click here) ...
View in English View in Hindi

Find the least number which when multiplied with 74088 will make it a perfect square ?

A)
42

B)
44

C)
46

D)
48


Correct Answer :

42


Explanation :

74088 = 2 * 2 * 2 * 3 * 3 * 3 * 7 * 7 * 7
= (2*2) * (3*3) * (7*7) * (2*3*7)
Least number which should be multiplied to 74088 to make it a Perfect square = 2 * 3 * 7 = 42

Find the least number by which 175760 be devided to make it a perfect cube ?

A)
10

B)
20

C)
100

D)
5


Correct Answer :

10


Explanation :

175760 = 24 x 5 x 13 3
= 23 x 2 x 5 x 133
To make perfect cube, it must be divided by 2 x 5 = 10

√(248 + √(52+ √144)) = ?

A)
14

B)
16

C)
16.6

D)
18.8


Correct Answer :

16


Explanation :

√(248 + √(52 + √144))
=> √(248 + √(52 + 12))
=> √(248 + √64)
=> √(248 + 8)
=> √256
=> 16

250 / √? = 10

A)
25

B)
250

C)
625

D)
2500


Correct Answer :

625


Explanation :

Let 250 / √x = 10.
Then √x= 250 / 10 = 25
Thus, x = 625

√(4/3) - √(3/4) = ?

A)
1/2√3

B)
- 1/2√3

C)
1

D)
2√3


Correct Answer :

1/2√3


Explanation :

√(4/3) - √(3/4)
= 2/√3 - √3/2
= (4 - 3)/2√3
= 1/2√3

If √2n = 64, then the value of n is ?

A)
2

B)
4

C)
6

D)
12


Correct Answer :

12


Explanation :

√2n = 64
⇒ 2n/2 = 26
⇒ n/2 = 6
⇒ n = 12

(√5 - √3)/ (√5 + √3) is equal to ?

A)
4 + √15

B)
4 - √15

C)
1/2

D)
1


Correct Answer :

4 - √15


Explanation :

(√5 - √3)/ (√5 + √3)
= (√5 - √3) / (√5 + √3)
= (√5 - √3)2 / (5 - 3)
= (5 + 3 - 2√5 x 3) / 2
= 2 (4 - √15) / 2
= (4 - √15)

3√(0.027/0.125) = ?

A)
0.6

B)
0.3

C)
0.5

D)
0.2


Correct Answer :

0.6


Explanation :

3√(27*1000/125*1000) => 3√(27/125) => 3√27 / 3√125
=> 3√(33) / 3√(53) =>3/4
=> 0.6

The largest three digit number which is a perfect cube is?

A)
986

B)
729

C)
981

D)
864


Correct Answer :

729


Explanation :

93 = 729 and 103 = 1000
So the required number = 729

3√(√ 729) = ?

A)
9

B)
3

C)
8

D)
6


Correct Answer :

3


Explanation :

3√(√ 729) = 3√(√ (272))= 3√27
=> 3√(33) = 3

What is the smallest number by which 1400 be divided to make it a perfect cube?

A)
130

B)
145

C)
160

D)
175


Correct Answer :

175


Explanation :

1400 = 23 * 52 * 7
To make it a perfect cube, it must be divided by
52 *7 = 175

Find the least number by which 175760 be multiplied to make it a perfect cube?

A)
100

B)
160

C)
80

D)
27


Correct Answer :

100


Explanation :

175760 = 24 *5 *133
To make it a perfect cube it must be multiplied by
22 * 52 = 100.

The cube root of 5.832 is ?

A)
0.18

B)
0.28

C)
2.8

D)
1.8


Correct Answer :

1.8


Explanation :

3√5.832 = 3√(5832/1000) =3√5832 / 3√1000 = 18/10 =1.8

The difference of squares of two consecutive odd numbers is always ?

A)
divisible by 8

B)
divisible by 2

C)
divisible by 16

D)
divisible by 18


Correct Answer :

divisible by 8


Explanation :

Let two odd numbers be (2x + 1) and (2x + 3)
Difference between the squares= (2x + 3)2 - (2x + 1)2
= (4x2 + 12x + 9) - (4x2 + 4x + 1)
= 8x+8
= 8(x+1) which is always divisible by 8

Find the value of the following √156.25 + √0.0081 - √0.0361 ?

A)
13.4

B)
15.4

C)
12.4

D)
17.4


Correct Answer :

12.4


Explanation :

√156.25 + √0.0081 - √0.0361
=12.5+0.09-0.19
=12.4

Find the value of √ (0.25 * 2.25) ?

A)
0.075

B)
0.705

C)
0.75

D)
7.500


Correct Answer :

0.75


Explanation :

√ (0.25 * 2.25)
=0.5*1.5
=0.75

Latest Updates

Indian Geography

What is the approximate distance between earth and the moon?

Indian History

In which year was the battle of ‘Koregaon Bhima’ fought?

The approach that is very useful in organizing the content in history is.

General Knowledge of India

NITI Aayog stands for _____.

General Knowledge of MP

India’s first Ramayan art museum was established at?

Errors Identification

Read the sentence carefully and choose the option that has an error in it:
The management’s trusted employee was suspected of stealing large sum of money.

Read the sentence carefully and choose the option that has an error in it:
The teacher asked the child to repeat again because he spoke feebly.

Fill in the blank

Fill in the blank with the most appropriate preposition in the given sentence.
Let’s sit _________ the shade of this beautiful tree.

Choose the most appropriate determiner for the given sentence.
________of what he said was very sensible.

Substitution

Choose the option that substitutes the given phrase appropriately.
A work of art made by carving

Correct sentence

Choose the option that best transforms the sentence into its Indirect form:
‘What country do you come from?’ said the police officer.

Alternative Phrase

Choose the option that best explains the highlighted expression:
All human beings have feet of clay.

Fill in the blank

Choose an appropriate modal for the given sentence:
My doctor said that I_____ stop smoking as one of my lungs got infected.

Choose the appropriate prepositions for the given sentence:
My parents have been married ________ forty-nine years, but you can still see the love ________ their eyes.

Choose the appropriate conjunction for the given sentence:
______ it rains, the college will declare the holiday.

Antonyms

Choose the appropriate antonym for the highlighted word in the given sentence.
The family protracted their visit by several days.

Tenses

Choose the appropriate tenses to fill in the blanks in the given sentence:
Please _________ a noise. Ritu __________ to sleep.

Synonyms

Choose the appropriate synonym for the highlighted word in the given sentence.
Does he really expect us to believe such a flimsy excuse?