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Section - 22 Question - 10

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Section - 22 Question - 10

by camitava » Wed Sep 19, 2007 3:43 am
Guys, I need help - Refer the qs below -
The numbers in which of the following pairs do NOT have a pair of distinct prime divisors in common ?
(A) 10 and 20
(B) 12 and 18
(C) 24 and 32
(D) 21 and 63
(E) 22 and 88
Hey first point is - I am not being able to get out the meaning of it.
second point is - What will be the approach & what is the answer?

OA is C
Correct me If I am wrong


Regards,

Amitava
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by patrik.herzog » Wed Sep 19, 2007 5:02 am
Divisors of
10 = 1, 2, 5, 10
20 = 1, 2, 4, 5, 10, 20

Prime divisors of 10 and 20 are: 2, 5

Now, do it for the rest of the pairs and you'll see that all except 24 and 32 have at least 2 identical prime divisors..

Hence, answer C
Last edited by patrik.herzog on Wed Sep 19, 2007 6:40 am, edited 1 time in total.
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by kajcha » Wed Sep 19, 2007 5:29 am
Ans is C

Q is asking which set of numbers does not have a COMMON PAIR of PRIME nos as factors

A.10 and 20 - 2,5 are common factors
B. 12 and 18 - 2,3 are common factors
D. 21 and 63 - 3,7 are common factors
E. 22 and 88 - 2,11 are common factors

C - 24 has 2 and 3 as factors
but 32 has only 2 as factor
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by tanyajoseph » Wed Sep 19, 2007 2:31 pm
Guys, I need help - Refer the qs below -
Quote:
The numbers in which of the following pairs do NOT have a pair of distinct prime divisors in common ?
(A) 10 and 20
(B) 12 and 18
(C) 24 and 32
(D) 21 and 63
(E) 22 and 88


Hey first point is - I am not being able to get out the meaning of it.
second point is - What will be the approach & what is the answer?


To answer your questions:
1. Question in layman terms - Of the choices listed below, which set of nos do not have two different prime numbers in common?
2. Approach to the question - Find the factors of the numbers in the choices and identify which pair of nos do not have two common factors.

Hope that helps :) Good luck!
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by camitava » Wed Sep 19, 2007 7:56 pm
Thanks a lot, guys! Now I have understood the problem.
Correct me If I am wrong


Regards,

Amitava
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by Scott@TargetTestPrep » Wed Jan 03, 2018 4:28 pm
The numbers in which of the following pairs do NOT have a pair of distinct prime divisors in common ?
(A) 10 and 20
(B) 12 and 18
(C) 24 and 32
(D) 21 and 63
(E) 22 and 88
We see that 10 and 20 have prime factors 5 and 2 in common and 12 and 18 have prime factors 2 and 3 in common, but 24 and 32 have only a 2 in common, so they do not have a pair of distinct prime factors in common.

Answer: C

Scott Woodbury-Stewart
Founder and CEO
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