please help

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please help

by anjaligeorge1 » Thu Jun 19, 2008 6:04 am
If a*b*c=60, where a, b, and c are integers greater than 1, a+b+c=?

(1) a+b=8
(2) Both a and b are odd numbers.

the answer says B .why cant it be D coz a ,b , & c can be 3 , 5 , & 4
as per statement 1 - a+ b : 3 + 5 = 8

can anyone help with this .

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Re: please help

by durgesh79 » Thu Jun 19, 2008 6:15 am
anjaligeorge1 wrote:If a*b*c=60, where a, b, and c are integers greater than 1, a+b+c=?

(1) a+b=8
(2) Both a and b are odd numbers.

the answer says B .why cant it be D coz a ,b , & c can be 3 , 5 , & 4
as per statement 1 - a+ b : 3 + 5 = 8

can anyone help with this .
a,b,c could be 2,6,5 also .... thats why A is not suff.

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by ildude02 » Thu Jun 19, 2008 11:01 am
An other way of solving this is, we know that the prime factors of 60 = 2 x 2 x 3 x 5. Considering statement 1, a+ b = even , so a and b must be odd or a and b must be even. So a and b can 5 and 3 if odd, or they can 2 and 6 when considering even. So we know a+b+c can vary and is INSUFF.

Statement 2: clearly says a and b are odd and the two of the prime factors are odd as well3, 5). The other number C can only be 4. So there is only one value of a+b+c.

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Answer must be C.

by onurh20 » Thu Jun 19, 2008 11:25 am
The answere must be B.