Aptitude - Problems on H.C.F and L.C.M - Discussion
Discussion Forum : Problems on H.C.F and L.C.M - General Questions (Q.No. 9)
9.
The product of two numbers is 2028 and their H.C.F. is 13. The number of such pairs is:
Answer: Option
Explanation:
Let the numbers 13a and 13b.
Then, 13a x 13b = 2028
ab = 12.
Now, the co-primes with product 12 are (1, 12) and (3, 4).
[Note: Two integers a and b are said to be coprime or relatively prime if they have no common positive factor other than 1 or, equivalently, if their greatest common divisor is 1 ]
So, the required numbers are (13 x 1, 13 x 12) and (13 x 3, 13 x 4).
Clearly, there are 2 such pairs.
Discussion:
94 comments Page 9 of 10.
Pallavi said:
1 decade ago
Why not (13*6, 13*2) be another pair?
Deepika said:
1 decade ago
Can anyone explain in a simple way?
Nikhil said:
1 decade ago
In that case HCF would become 26.
Pragya said:
1 decade ago
Why are we considering coprimes?
Yash Srivastava said:
1 decade ago
HCF of 26 and 78 is 2 not 13.
Vaani said:
1 decade ago
Why should we take co-primes?
Garima said:
8 years ago
Can we take a pair of 13, 1?
Dinesh said:
1 decade ago
Why to take the pairs of 12?
Sami said:
9 years ago
How to choose the pairs?
Utsavchavda said:
1 decade ago
Meaning of co-prime ?
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