Aptitude - Square Root and Cube Root - Discussion

Discussion Forum : Square Root and Cube Root - General Questions (Q.No. 3)
3.
The least perfect square, which is divisible by each of 21, 36 and 66 is:
213444
214344
214434
231444
Answer: Option
Explanation:

L.C.M. of 21, 36, 66 = 2772.

Now, 2772 = 2 x 2 x 3 x 3 x 7 x 11

To make it a perfect square, it must be multiplied by 7 x 11.

So, required number = 22 x 32 x 72 x 112 = 213444

Discussion:
80 comments Page 8 of 8.

Bilal said:   1 decade ago
How should we get to know that we have 2 tak out the lcm of that 3 no.

Nancy said:   1 decade ago
I totally cant understand the logic why we have to multiply 7 and 11. Can anyone explain this clearly?

Tamil said:   1 decade ago
How separate 2772 into 2*2*3*3*7*11?

Neha said:   1 decade ago
3|21 36 66
|7 12 22
2|6 11 there fore lcm =3*7*2*6*11=2772
hence these can be written as
3*7*2*2*3*11
here 3 is of two times &2is of two times there fore remaining is 7&11 in order to have all squares 7*11 is taken
ans:213444

Devi said:   1 decade ago
Any shortcut way to find out L.C.M of two or more number.

Vishal said:   1 decade ago
Because 7 and 11 are don't have common factors.

Doov said:   1 decade ago
Why we should multiply 7 with 11?

Karthik said:   1 decade ago
To make it a perfect square
Why should v multipled 7x11 with the lcm ?

Bujji said:   1 decade ago
Why should multiplied 7 with 11 ?

Janhavi said:   1 decade ago
How come the 2772? Please give me explanation.


Post your comments here:

Your comments will be displayed after verification.