The least common multiplier of A and B is 120, the ratio of A and B is 3:4, what is the largest common divisor?
How do u attack this problem? .. what are the approaches to take.
[spoiler]OA: 10
We know that A * B = LCM * GCD and we now LCM = 120.
So we get A *B = 120* GCD.
Now how does the ratio of the two numbers play out.
Pls explain in detail
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LCM and GCD
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vittalgmat
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hamxa
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I will approach this in a different way:
factors of 120 = 2*2*2*3*5
now ratio of A and B is 3:4.
WHICH MEANS A=multiple of 3
and B = multiple of 4
Now: multiple of both has to be the same as its a ratio.
In 120 if we take out 3 and 4, we are left with the factors 2 & 5.
hence A and B should have 2 & 5 in them
A=3*10 =30
B=4*10 = 40
now GCD of 30 & 40 = piece of cake
factors of 120 = 2*2*2*3*5
now ratio of A and B is 3:4.
WHICH MEANS A=multiple of 3
and B = multiple of 4
Now: multiple of both has to be the same as its a ratio.
In 120 if we take out 3 and 4, we are left with the factors 2 & 5.
hence A and B should have 2 & 5 in them
A=3*10 =30
B=4*10 = 40
now GCD of 30 & 40 = piece of cake
