[#12] 2 Min. Challenge: Even

Question

Rules 

1. Time yourself 
2. Solve this problem on a sheet of paper   
3. type in your solution and the time, if possible. 

a, b, c are integers. Is (a*b*c)! even? 

(1) a^2-5a=-6 
(2) bc>0

kpadma · Answer

Ans: E From A) a = 3 or -2 NOT SUFF From B) bc > 0 ; a is not given; NOT SUFF From A & B ; bc > 0 and a =3 or -2. so a * b * c could be postive integer or negative integer << NOT SUFF Thus, answer E

anandnk · Answer

A) not sufficient because a = 2 or a = 3 and any one of b and c could be 0
B) not sufficient because a could be zero.

Combine you get abc > 1 .A factorial of any number > 1 is always even

C should be the answer.

Makky07 · Answer

That's most certainly true Anandnk. Factorials will always be even except 1!

C is the answer.

cbrf3 · Answer

Agree with Anandk............C should be it!!

kpadma · Answer

I made a stupid mistake. 
Ans is C and Anand explanation is the correct.

Praetorian · Answer

C is the correct answer. good work.

try to write down all your times. this data will be useful for us in our new simulator project.

n! is always even except when n=1 or 0 . Now from (1), we know that a is a non zero number and that its not 1. From (2) we know that b and c are non zero 

Therefore, from (1) and (2) together we can conclude that (a*b*c)! is even 

Hence C

[#12] 2 Min. Challenge: Even

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