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:
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 3 of 8.
Maha said:
1 decade ago
Take LCM for 21, 36 and 66 we get 2*2*3*3*7*11 = 2772,
2 and 3 are came 2 times we will get perfect square so multiply this term with 7*11 so we get 2*2*3*3*7*7*11*11 = 213444.
2 and 3 are came 2 times we will get perfect square so multiply this term with 7*11 so we get 2*2*3*3*7*7*11*11 = 213444.
Aayush said:
5 years ago
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.
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.
(4)
Deepu said:
1 decade ago
The lcm of 21,36,66=2772
I have a simple method.
213444is divisible by 21 comes 10164
and 36 to comes 5929
and 6 to comes 3234
So finaly it is divisible by 3 numbers.
I have a simple method.
213444is divisible by 21 comes 10164
and 36 to comes 5929
and 6 to comes 3234
So finaly it is divisible by 3 numbers.
Raju kaki said:
1 decade ago
3/21,36,66
2/7,12,22
7,6,11
so l.c.m=3*2*7*6*11
=3^2*2^2*7*11
to make perfect square we have to multiply with 7 and 11the it turns
=3^2*2^2*7^2*11^2
2/7,12,22
7,6,11
so l.c.m=3*2*7*6*11
=3^2*2^2*7*11
to make perfect square we have to multiply with 7 and 11the it turns
=3^2*2^2*7^2*11^2
Sheikh Muhammad Ammar said:
1 decade ago
I think according to maths rule 7 & 11 must be multiplied on both ends.
Hence 2^2*3^2*7*11*(7*11) = 2772*7*11.
= 2^2*3^2*7^2*11^2 = 213444.
Hence 2^2*3^2*7*11*(7*11) = 2772*7*11.
= 2^2*3^2*7^2*11^2 = 213444.
Maniram said:
6 years ago
Since 213444 is divisible by all of the three number i.e. 21, 36, 66 so its the answer. We don't even have to see the second option.
(6)
Anomi said:
8 years ago
21 is having a factor as 7 and 3.
So check each option whether it is divisible by 7 or not.
So option a is only divisible by 7.
So check each option whether it is divisible by 7 or not.
So option a is only divisible by 7.
Raju said:
1 decade ago
2x2x3x3x7x11 = 2772.
Here all are pair numbers but 7 & 11 are single numbers that's why we multiple by 7 & 11 again.
Here all are pair numbers but 7 & 11 are single numbers that's why we multiple by 7 & 11 again.
Prashant said:
1 decade ago
For LCM 21, 36 & 66:
3/21 36 66.
2/7 12 22.
3/7. 6. 11.
2/7. 2. 11.
7. 1. 11.
3 x 3 x 2 x 2 x 7 x 11 = 213444.
3/21 36 66.
2/7 12 22.
3/7. 6. 11.
2/7. 2. 11.
7. 1. 11.
3 x 3 x 2 x 2 x 7 x 11 = 213444.
Kik nil88 said:
1 decade ago
21 36 66 are divisible by 3.
Now check the options. And then find the least no. Which is also divisible by 3.
Now check the options. And then find the least no. Which is also divisible by 3.
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