the product of A and B

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the product of A and B

by sanju09 » Wed May 02, 2012 5:03 am
If Q and R are integers and A and B represent digits and 1/Q = 0.0A and 1/R = 0.0B then one possible value of the product of A and B is:
(A) 6
(B) 12
(C) 15
(D) 18
(E) 20



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by klmehta03 » Wed May 02, 2012 5:59 am
IMO E. Only 20 can be a product of digits (2 & 10) whose inverse can result in integers.
OA pls?

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by shantanu86 » Wed May 02, 2012 6:02 am
Hi klmehta03,

Your answer is correct but explanation is wrong.

IMO [spoiler][E][/spoiler]..

From question-
Q =100/A and
R= 100/B

Since A and B are single digits possible values are-
1, 2, 4, 5

Thus, option [spoiler][E][/spoiler] is correct one.

Hope it helps!!
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by spartacus1412 » Wed May 02, 2012 6:04 am
IMO E 20
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by jrakhe » Thu May 03, 2012 4:02 pm
1/Q = 0.0A => A = 100/Q
1/R = 0.0B => B = 100/R

So, A x B = (100/Q) X (100/R)

A x B = (100 * 100)/(Q*R)

Now the factor of 100 is 2 and 5. And from the answer choices only 20 has 2 and 5 as factors so answer is 20. (E)