If r and s are positive integers, r/15 is an integer and s/12 is an in

Question

If r and s are positive integers, r/15 is an integer and s/12 is an integer, is rs a multiple of 210?

(1) r/20 is an integer.
(2) s/28 is an integer.

raarun · Answer

Multiple of 210 are 210 ,420,630,840,1050 etc

Stmnt 1 :
Since r/15 and r/20 are integers r can be 60 ,120,180 etc
The product of rs may or may not be a multiple of 210 based on the values of r and s
e.g r=120 s=84 rs is a multiple of 210
e.g r=60 s=36 rs is not a multiple of 210
Insufficeint

Stmnt 2:
Since s/12 and s/28 are integers s can have the values 84,168 etc
r can be 15,30,45 etc from the question stem so it always is a multiple of 5
so rs will always be a multiple of 210
Sufficient

Ans B

ashikaverma13 · Answer

How is r being a multiple of 5 relevent here?

All we need to figure out is the LCM 84 and above multiplied with multiples of 15 will always lead to a multiple of 210 right? which is true for this statement hence it is enough.

If r and s are positive integers, r/15 is an integer and s/12 is an in

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