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osanseviero
A person has 5 coins of different values. ¿How many different additions can I make?
Is the question how many different additions can you make or how many different changes can you make with 5 coins?
I saw 31 as a result in some website, but I would like someone to explain how to solve this
To do additions you have to have at least 2 coins. You can select 2 coins in 5C2 ways. With three coin additions: 5C3 ways With four coin additions: 5C4 ways With five coin additions: 5C5 ways Add them all up.
But if you count the single coins itself (no additions) then 5C1 ways. So you add them all and you get 31. So when they say "sums" they don't mean additions but how many different changes can you make with 5 coins.
Oh...so it is 26, but if you can use the coins by themselves, you add 5. Thanks :D