For integers x and y, if (x+2)(y+3) is even then 4xy must be divisible by:
Choose the most appropriate option:
A) 4
B) 8
C) 9
D) 10
E) 12

Rationale: just looking at the question , ( x + 2 ) ( y + 3 ) could be even * even , odd * even , or even * odd in order for the whole expression to be even . however , just looking at 4 xy , since x * y will always be an integer , it will always be divisible by 4 . 4 divided by 4 is 1 , hence preserving x * y . answer : a . 4
Answer: A