If r is even and s is odd, which of the following is odd?  Choose the most appropriate option:
A) rs B) 5rs C) 6(r^2)s D) 5r + 6s E) 6r + 5s
Just checking options (In case you have difficulty then choose values of r=2 and t=1)   r = even   s= Odd   A. rs = Even*Odd = EvenINCORRECT   B. 5rs = Odd*Even*Odd = EvenINCORRECT   C. 6(r^2)s = 6*(Even^2)*Odd = EvenINCORRECT   D. 5r + 6s = 5*Even + 6*Odd = Even+Even = EvenINCORRECT   E. 6r + 5s = 6*6r + 5sven + 5*Odd = 6r + 5sven+Odd = OddCORR6r + 5sCT   Answer: option 6r + 5s
<result>E</result>
If r is even and s is odd, which of the following is odd?