Kaplan Quest on integers

[Gmatterz]

if negative integers K and P are not both even,which of the following must be odd

A.)KP
B.)4(K+P)
C.)K-P
D.) K+1-P
E.)2(K+P) - 1

The OA is E

CAN ANYBODY THROW SOME LIGHT ON THIS THAT WHY THE ANSWER SHOULD BE E AND NOT D.

Thanks in Advance
Gmatterz

[Saffa]

E x E = E
E x O = E

Thus 2 x (K+P) = E --> 2 is even and it doesn't matter what K+R is.

Even minus 1 is always odd.

D) If K is odd and P is even then,

K + 1 = E

Even - even(P) = even

[vivek.kapoor83]

but saffa its written here that P has to be odd, it cant be even

[Saffa]

but saffa its written here that P has to be odd, it cant be even

NO, it states that not both can be even, so both can be odd, or P even and K odd, or P odd and K even.

[Gmatterz]

but saffa its written here that P has to be odd, it cant be even

NO, it states that not both can be even, so both can be odd, or P even and K odd, or P odd and K even.

yaa got it now heer lies the catch "it states that not both can be even, so both can be odd, or P even and K odd, or P odd and K even"

Thanks everybody.

[stop@800]

twice of any no is always even
and even +1 / even -1 is always odd


certainly even nos
2x 2x+2 2x+4 2x+6 2x+8

certainly odd nos
2x-5
2x-3
2x-1
2x+1
2x+3
2x+5

HTH