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(a*b)/c an odd integer?

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by himu » Tue Jul 02, 2013 3:42 am
If a, b and c are integers, is (a*b)/c an odd integer?

When a is divided by c, the quotient is an odd integer.
When b is divided by c, the quotient is an odd integer.
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Source: — Data Sufficiency |

by Brent@GMATPrepNow » Tue Jul 02, 2013 5:46 am
himu wrote:If a, b and c are integers, is (ab)/c an odd integer?

(1) When a is divided by c, the quotient is an odd integer.
(2) When b is divided by c, the quotient is an odd integer.
The word "quotient" here leaves room for different interpretations. Consider this example:
When 17 is divided by 5 the quotient is 3 and the remainder is 2
When 15 is divided by 5 the quotient is 3 and the remainder is 0
So, does statement 1 (When a is divided by c, the quotient is an odd integer.) allow for the remainder to be a number other than zero?

Having said all of that, the answer is E in either case.

Let's jump straight to . . .

Statements 1 and 2 combined:
There are several sets of values that satisfy both statements. Here are two:
Case a: a = 3, b = 3 and c = 1, in which case ab/c is an odd integer
Case b: a = 6, b = 6 and c = 2, in which case ab/c is an even integer
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer = E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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