If a*b*c=60, where a, b, and c are integers greater than 1

Question

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.

Zarrolou · Answer

If a*b*c=60, where a, b, and c are integers greater than 1, a+b+c=? 
 60=2*2*3*5

(1) a + b = 8 
a could be 5 and b could be 3 (or the opposite) => a+b+c=5+3+4=12
a could be 6 and b could be 2 (or the opposite)=> a+b+c=6+2+5=13
Not sufficient

(2) Both a and b are odd numbers. 
So a=5 and b=3 (or the opposite) in both cases a+b+c=12
Sufficient

Bunuel · Answer

If a*b*c=60, where a, b, and c are integers greater than 1, a+b+c=?

60=2^2*3*5.

(1) a + b = 8. If a=3 and b=5, then c=4 and a+b+c=12 but if a=2 and b=6, then c=5 and a+b+c=13. Not sufficient.

(2) Both a and b are odd numbers. Since both of them must be greater than 1, then they must be 3 and 5, thus c=4 and a+b+c=12. Sufficient.

Answer: B.

stunn3r · Answer

Thanks for sharing your approach .. though I solved it under 2minutes 30 seconds but my approach was quite mechanical and this question does not deserve more than 100 seconds.

bumpbot · Answer

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If abc=60, where a, b, and c are integers greater than 1

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