Answer : 50
Question says whole number , so we start with 0
0 + 99 = 99 (0,99)
1 + 98 = 99 (1,98)
2 + 97 = 99 (2,97)
-
-
49 + 50 = 99 (40,50)
We will get the same sum , if we put the numbers in reverse
50 + 49 = 99
-
-
99 + 0 = 99
So there are 50 pairs of whole numbers have a sum of 99
