Sail E0 Webinar

Quantitative Aptitude

SQUARE ROOT AND CUBE ROOT MCQs

Square Roots, Cube Roots, Squares And Square Roots

Total Questions : 547 | Page 31 of 55 pages
Question 301.

`sqrt((.081 xx .484)/(.0064 xx 6.25))` is equal to  :


  1.    0.9
  2.    0.99
  3.    9
  4.    99
 Discuss Question
Answer: Option B. -> 0.99

Sum of decimal places in the numerator and  denominator under the radical sign being the same, we remove the

decimal.

`:.`  Given exp =    `sqrt((.081 xx .484)/(.0064 xx 6.25))` = `sqrt((81 xx 484)/(64 xx 625))`

                        =  `(9 xx 22)/(8 xx 25)` =  0.99



Question 302.

The approximate value of `(3sqrt(12))/(2sqrt(28))` `-:` `(2sqrt(21))/(sqrt(98))`  is :


  1.    1.0605
  2.    1.0727
  3.    1.6007
  4.    1.6026
 Discuss Question
Answer: Option A. -> 1.0605

`(3sqrt(12))/(2sqrt(28))` `-:` `(2sqrt(21))/(sqrt(98))` =`(3sqrt(12))/(2sqrt(28))` x `(sqrt(98))/(2sqrt(21))`

 =`(3sqrt(4 xx 3))/(2sqrt(4 xx 7))` x` (sqrt(49 xx 2))/(2sqrt(21))` =  `(6sqrt(3))/(4sqrt(7))` x `(7sqrt(2))/(2sqrt(21))`

= `(21sqrt(6))/(4sqrt(7 xx 21))` =   `(21sqrt(6))/(28sqrt(3))`     = `3/4`` sqrt(2)`=  `3/4` x 1.414 =  3 x 0.3525 = 1.0605




Question 303.

Given `sqrt(2) `= 1.414.  The value of `sqrt(8) + 2sqrt(32) - 3sqrt(128) + 4sqrt(50)` is :


  1.    8.426
  2.    8.484
  3.    8.526
  4.    8.876
 Discuss Question
Answer: Option B. -> 8.484

Given exp. = `sqrt(8) + 2sqrt(32) - 3sqrt(128) + 4sqrt(50)`

                  = `sqrt(4 xx 2) + 2sqrt(16 xx 2) - 3sqrt(64 xx 2) + 4sqrt(25 xx 2)`

                 = `2sqrt(2) + 8sqrt(2) - 24sqrt(2) + 20sqrt(2)`     = `6sqrt(2)`  =  6 x 1.414 = 8.484. 


Question 304.

`sqrt(50) xx sqrt(98)` is equal to :


  1.    63.75
  2.    65.95
  3.    70
  4.    70.25
 Discuss Question
Answer: Option C. -> 70

`sqrt(50) xx sqrt(98)` =  `sqrt(50 xx 98)` = `sqrt(4900)` = 70.


Question 305.

If `3sqrt(5) + sqrt(125)`  = 17.88, then what  will be  the value of `sqrt(80) + 6sqrt(5)`  ?


  1.    13.41
  2.    20.46
  3.    21.66
  4.    22.35
 Discuss Question
Answer: Option D. -> 22.35

`3sqrt(5) + sqrt(125)`  = 17.88,    `rArr` ` 3sqrt(5) + sqrt(25 xx 5)`  =  17.88

   `rArr`  `3sqrt(5) + 5sqrt(5)` = 17.88    `rArr` ` 8sqrt(5)` = 17.88    `rArr` ` sqrt(5) `=  2.235.

`:.`  `sqrt(80) + 6sqrt(5)` =  `sqrt(16 xx 5) + 6sqrt(5)` = `4sqrt(5) + 6sqrt(5)` =  `10sqrt(5)`

= (10 x 2.235) =  22.35



Question 306.

The value of `(sqrt(80) - sqrt(112))/ (sqrt(45) - sqrt(63))`  is  :


  1.    `3/4`
  2.    `1 1/3`
  3.    `1 7/9`
  4.    `1 3/4`
 Discuss Question
Answer: Option B. -> `1 1/3`

`(sqrt(80) - sqrt(112))/ (sqrt(45) - sqrt(63))`  = `(sqrt(16 xx 5) - sqrt(16 xx 7))/(sqrt(9 xx 5) - sqrt(9 xx 7))`

= `(4sqrt(5) - 4sqrt(7))/(3sqrt(5) - 3sqrt(7))` = `(4(sqrt(5) - sqrt(7)))/(3(sqrt(5) - sqrt(7)))` =  `4/3` =  `1 1/3`


Question 307.

`(sqrt(24) + sqrt(216))/(sqrt(96))` =  ?


  1.    `2sqrt(6)`
  2.    2
  3.    `6sqrt(2)`
  4.    `2/sqrt(6)`
 Discuss Question
Answer: Option B. -> 2

`(sqrt(24) + sqrt(216))/(sqrt(96))`  = `(sqrt(4 xx 6) + sqrt(36 xx 6))/(sqrt(16 xx 6))`

= `(2sqrt(6) + 6sqrt(6))/(4sqrt(6))` =`(8sqrt(6))/(4sqrt(6))` =  2


Question 308.

By how much does `sqrt(12) + sqrt(18)` exceed `sqrt(3) + sqrt(2)`  ?


  1.    `sqrt(2) - 4sqrt(3)`
  2.    `sqrt(3) + 2sqrt(2)`
  3.    `2(sqrt(3) - sqrt(2))`
  4.    `3(sqrt(3) + sqrt(2))`
 Discuss Question
Answer: Option B. -> `sqrt(3) + 2sqrt(2)`

`(sqrt(12) + sqrt(18)) - (sqrt(3) + sqrt(2))` = `(sqrt(4xx3) +sqrt(9xx2)) - (sqrt(3) + sqrt(2))`

`(2sqrt(3) + 3sqrt(2)) - (sqrt(3) +sqrt(2))` = `(2sqrt(3) - sqrt(3)) + (3sqrt(2) - sqrt(2))`

= `sqrt(3) + 2sqrt(2)`.



Question 309.

`(2sqrt(27) - sqrt(75) + sqrt(12))` is equal to :


  1.    `sqrt(3)`
  2.    `2sqrt(3)`
  3.    `3sqrt(3)`
  4.    `4sqrt(3)`
 Discuss Question
Answer: Option C. -> `3sqrt(3)`

`(2sqrt(27) - sqrt(75) + sqrt(12))` = `2sqrt(9 xx 3) - sqrt(25 xx 3) + sqrt(4 xx 3)`

                 = `6sqrt(3) - 5sqrt(3) + 2sqrt(3)`  =  `3sqrt(3)`


Question 310.

If `sqrt(1 + 55/729)` = 1 + `x/27` , then the value of `x` is :


  1.    1
  2.    3
  3.    5
  4.    7
 Discuss Question
Answer: Option A. -> 1

`sqrt(1 + 55/729)` = 1 + `x/27`  `rArr` `sqrt(784/729)` =  `(27 + x)/(27)` `rArr` `28/27` =` (27 + x)/(27)`

                            `rArr`  27 + `x` = 28  `rArr`  `x` = 1.


Latest Videos

Latest Test Papers