JAI HIND wrote:
If a and b are integers, is b even?
(1) 3a + 4b is even.
(2) 3a + 5b is even.
I got the answer, but it took some time working out! Wanted to check any shorter methods!
My answer is C
For a sum of two numbers to be even..two numbers can either
EVEN + EVEN
ODD + ODD
(1) 3a + 4b is even ==> 4b cannot be odd so it must be the even + even combination. B could be odd or even ==> Insufficient
(2) 3a + 5b is even ==> Could be EVEn + EVEN, ODD + ODD combo. Insufficient
(1) + (2) ==> From (1), we know that 3a must be even...so in (2) 5b must be even as well ==> b = even
Don't be afraid to take a flying leap of faith.. If you risk nothing, than you gain nothing...