An infinite number.
41
Infinite
There are infinitely many pairs of numbers that sum to 59. One such is 0.1 and 58.9
There are infinitely many pairs. For example 23.5 and 75.5 or -3 and 102.
If you include negative numbers, the list is infinite.
The sum of the first five whole numbers is 10.
The sum of whole numbers 1 through 30 is 465.
100
20 of them
3 pairs of whole numbers add up to 7: 1 +6, 2+5, 3+4 (0+7 also equals 7, but zero is not a whole number)
6
There are infinitely many pairs of numbers that sum to 59. One such is 0.1 and 58.9
49 of them.
There 4 pairs of primes that can give a sum 40 in addition. They are (3,37), (11,29), (17,23),(19,21).
Just 3 + 3
100
Only one pair.
number of pairs of odd numbers whose sum is 32: 8pairs of odd numbers whose sum is 32:1, 313, 295, 277, 259, 2311, 2113, 1915, 17
There are two pairs of prime numbers that express 18 as the sum of two prime numbers: 7 + 11 = 18 and 5 + 13 = 18.