Cecilia, Robbie, and Briony all bought stamps. The number of stamps Cecilia purchased was equal to a single digit. The number of stamps only one of them purchased was divisible by 3. The number of stamps one of them bought was an even number. Which of the following could represent the numbers of stamps each purchased?
A. 3, 8, 24
B. 7, 9, 17
C. 6, 9, 12
D. 5, 15, 18
E. 9, 10, 13
The OA is E.
Please, can any expert explain this PS question for me? I would like to know how to solve it in less than 2 minutes. I need your help. Thanks.
Cecilia, Robbie, and Briony all bought stamps...
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A. 3, and 24 are BOTH divisible by 3, so NOT VALID
B. 7, 9, 17 are ALL ODD, so NOT VALID
C. 6, 9, 12 are ALL divisible by 3, so NOT VALID
D. 15, and 18 are BOTH divisible by 3, so NOT VALID
E. Only 9 is divisible by 3, only 10 is even, 13 is not divisible by three and not even so VALID
The OA is E.
B. 7, 9, 17 are ALL ODD, so NOT VALID
C. 6, 9, 12 are ALL divisible by 3, so NOT VALID
D. 15, and 18 are BOTH divisible by 3, so NOT VALID
E. Only 9 is divisible by 3, only 10 is even, 13 is not divisible by three and not even so VALID
The OA is E.