Counting & ProbabilityChallengeNumber Theory Toolkit ShareNumber Theory Toolkit · Challenge problemHow many different sums can you make by adding two DIFFERENT numbers from {1,3,5,7,9}\{1, 3, 5, 7, 9\}{1,3,5,7,9}?A101010B999C888D777E666Check Show answer Walk through it step by step Practice more like this Review this concept