Aptitude - Square Root and Cube Root - Discussion

Discussion Forum : Square Root and Cube Root - General Questions (Q.No. 2)
2.
What should come in place of both x in the equation x = 162 .
128 x
12
14
144
196
Answer: Option
Explanation:

Let x = 162
128 x

Then x2 = 128 x 162

   = 64 x 2 x 18 x 9

   = 82 x 62 x 32

   = 8 x 6 x 3

   = 144.

x = 144 = 12.

Discussion:
35 comments Page 2 of 4.

Lavanya said:   1 decade ago
Shortcut method is applicable to only number 144 its not applicable to all 3 digit number. Try to give shortcut method to all numbers.

Harshi said:   1 decade ago
Your method is not correct the sqrt of 169 is 13 by your method it is also 12.

Sameer said:   1 decade ago
X = square root 128*162

= square root 64*2*81*2

= square root 64*81*4

= 8*9*2 = 144

Why answer is showing 12?

Kavya K said:   1 decade ago
@Sameer, that's not X = square root 128*162.

It should be X^2 = square root 128*162.

= square root 64*2*81*2.

= square root 64*81*4.

= 8*9*2.

X^2 = 144.

=> X = 144/2.

= 12.

Chandu said:   1 decade ago
@Sameer.

x square = 144.
Then x = square root of 144.
x = 12.

Azam said:   1 decade ago
Short method is that first take LCM of number given then make pairs.

Hammad said:   1 decade ago
We only find the value of x which is equal to 144. But 12 is the square root of 144. If we looking on the question he only demand the value of x which we find initially.

Mani Ratan said:   1 decade ago
Can we do 162=81*2 please solve it by other process?

Annoy singh said:   10 years ago
Because x = 144.

x = 12*12=144.

Parag said:   10 years ago
What is the meaning of ^?


Post your comments here:

Your comments will be displayed after verification.