How many distinct positive integers can be represented as the difference of two numbers in the set {1, 3, 5, 7, 9, 11, 13, 15, 17, 19}?

Guest Aug 5, 2022

#1**+3 **

We only need to calculate these

19 -17 = 2

19 - 15 = 4

19 - 13 = 6

19 - 11 = 8

19 - 9 = 10

19 - 7 = 12

19 - 5 = 14

19 - 3 = 16

19 -1 = 18

So....9 distinct (different) positive differences are possible

CPhill Aug 5, 2022