Question

Set s consists of the integers of the form r2+s, where r and s are integers such that and . How many integers in s are odd?

Answer 1

Answer:

There are 2 cases when r^2+s is odd

1. when r is odd and s is even

Total cases possible=3*2=6 (3,5,11,13, 27 and 29)

2. when r is even and s is odd

Total cases possible= 2*3=6 (5,7,9,17,19,21)

Total number of odd integers in Set s= 6+6-1=11 (we subtract 1, because 5 appears twice)