Tag: maths

Questions Related to maths

Find the square root of decimal 5.76.

maths square root square root of perfect square finding square root of a number square root of a perfect square

  1. $4.2$

  2. $2.4$

  3. $18.4$

  4. $4.23$

Show answer
Correct Option: B
Explanation:

$576=2^{6} \times 3^{6}=(2^{3} \times3)^2=(24)^{2}$

$100=2^{2} \times 5^{2}=(2 \times5)^{2}=(10)^{2}$
$\sqrt{5.76}=\sqrt{\dfrac{576}{100}}$=$\sqrt{({\dfrac{24}{10}})^{2}}$
$=\dfrac{24}{10}=2.4$

The square root of $144$ is 

maths square root square root of perfect square finding square root of a number square root of a perfect square

  1. $114$

  2. $442$

  3. $12$

  4. $24$

Show answer
Correct Option: C
Explanation:

$144 = 2\times2\times2\times2\times 3\times3$

$\sqrt{144} = \sqrt{2\times2\times2\times2\times 3\times3}=2\times2\times3=12$

Find the square root of $81$.

maths square root square root of perfect square finding square root of a number square root of a perfect square

  1. $9$

  2. $45$

  3. $18$

  4. $81$

Show answer
Correct Option: A
Explanation:

$ 81 = 3\times3\times3\times3$

$\sqrt{ 81} = \sqrt{3\times3\times3\times3}=3\times3=9$

Complete the repeated subtraction to find the square root of $225$.

maths square root square root of perfect square finding square root of a number square root of a perfect square

  1. $9$

  2. $45$

  3. $25$

  4. $15$

Show answer
Correct Option: D
Explanation:

$225 -1 = 224$ ,

$224 -3 = 221 $,
$221-  5 = 216$, 
$216 -7 = 209$,
$209 - 9= 200$ ,
$200 -11 = 189$
$189-  13 = 176$ , 
$176-  15 = 161$, 
$161 -17 = 144$,
$144- 19 = 125$
$125 - 21 = 104 $
$ 104-  23 = 81 $
$81-  25 = 56$
$ 56-  27 = 29$, 
$29 -29 = 0 = 15$ 
Therefore, D is the correct answer.

Simplify the following : $\sqrt { 0.0081 } $

maths square root square root of perfect square finding square root of a number square root of a perfect square

  1. $0.02$

  2. $0.09$

  3. $0.06$

  4. $0.05$

Show answer
Correct Option: B
Explanation:
$0.09$: Since $(0.09)(0.09)=0.0081$, 

$\sqrt{0.0081}=0.09$. 

You can also rewrite $0.0081$ as $81\times {10}^{-4}$

$\sqrt { 81\times { 10 }^{ -4 } } =\sqrt { 81 } \times \sqrt { { 10 }^{ -4 } } =9\times { \left( { 10 }^{ -4 } \right)  }^{ \frac { 1 }{ 2 }  }=9\times { 10 }^{ -2 }=0.09$

Which of the following is the value of $\displaystyle \sqrt { \sqrt [ 3 ]{ 0.000064 }  } $ ?

maths square root square root of perfect square finding square root of a number square root of a perfect square

  1. $0.004$

  2. $0.008$

  3. $0.02$

  4. $0.04$

  5. $0.2$

Show answer
Correct Option: E
Explanation:

$\sqrt[3]{0.000064}$$=$$0.04$

$\sqrt{0.04}$$=$$0.2$
 $\therefore \displaystyle \sqrt { \sqrt [ 3 ]{ 0.000064 }  } =0.2$
Hence, Option E is correct.

What is the value of $\sqrt{\frac{400}{25}}$?

maths square root square root of perfect square finding square root of a number square root of a perfect square

  1. 4

  2. 3

  3. 2

  4. 1

Show answer
Correct Option: A
Explanation:

$\sqrt{\dfrac{400}{25}}$
= $\dfrac{20}{5} = 4$.

Find the value of $\sqrt{\frac{484}{121}}$

maths square root square root of perfect square finding square root of a number square root of a perfect square

  1. 4

  2. 3

  3. 2

  4. 1

Show answer
Correct Option: C
Explanation:

$\sqrt{\dfrac{484}{121}}$
= $\dfrac{22}{11}$
= 2

Find the square root of 841.

maths square root square root of perfect square finding square root of a number square root of a perfect square

  1. 21

  2. 28

  3. 29

  4. 25

Show answer
Correct Option: C
Explanation:

$\sqrt{841}= \sqrt{29 \times 29}$
So, the square root of 841 is 29.

Subtracting which odd number will get the value of 288 for the square root of the number 484 using repeated subtraction method?

maths square root square root of perfect square finding square root of a number square root of a perfect square

  1. 25

  2. 23

  3. 27

  4. 29

Show answer
Correct Option: C
Explanation:

Repeated subtraction method: Subtract successive odd numbers from the given number starting from 1 till the difference becomes zero.
So, 484 - 1 = 483
483 - 3 = 480
480 - 5 = 475
475 - 7 = 468
468 - 9 = 459
459 - 11 = 448
448 - 13 = 435
435 - 15 = 420
420 - 17 = 403
403 - 19 = 384
384 - 21 = 363
363 - 23 = 340
340 - 25 = 315
315 - 27 = 288 
27 is the odd number, subtracting with 315 to get the value of 288.