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 4 of 10.
Pradeep said:
10 years ago
Why they take the two pair like (1, 12), (3, 4)?
Why not (12, 1), (4, 3)?
Why not (12, 1), (4, 3)?
Sami said:
10 years ago
How to choose the pairs?
Vinay ambidi said:
10 years ago
No someone asked why 5, 7 but if we multiply those numbers we will get 5*7 = 35.
That's why we have to take 1, 12 or 3, 4.
That's why we have to take 1, 12 or 3, 4.
Umesh said:
6 years ago
The answer is incorrect. The answer could also be 2 and 6.
Anik said:
9 years ago
Why not 2, 6? Please explain in clear.
Disha said:
8 years ago
Not getting this. Can anyone explain it to me?
Balachandra Padiyar said:
8 years ago
The co prime numbers those numbers which are having only one common factor that is 1
in (2&6) the factors are,
2 = 1,2.
6 = 1,2,3.
Here in 2&6 there are two factors ie, 1&2 hence they are not co primes hence it can't be used here.
Let us take 4&3,
4=1,2,4,
3=1,3,
Here only one common factor ie,1 and same for 12&1.
in (2&6) the factors are,
2 = 1,2.
6 = 1,2,3.
Here in 2&6 there are two factors ie, 1&2 hence they are not co primes hence it can't be used here.
Let us take 4&3,
4=1,2,4,
3=1,3,
Here only one common factor ie,1 and same for 12&1.
Shivangi said:
8 years ago
But Question is how many no of the pair. Not co factors. Please clear my doubt is no of pair means co-factor?
Kishan said:
8 years ago
The product of two numbers is 2028 and their HCF is 13 If the numbers of two digits find the numbers.
Can anyone answer me?
Can anyone answer me?
Nagendra said:
8 years ago
In the question, they doesn't mention about the co-prime numbers, right?
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