how many ways to get to nine in addition only using the number 3 and 1
help
3 + 3 + 3
3 + 3 + 1 + 1 + 1
3 + 1 + 1 + 1 + 1 + 1 +1
1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1
Let's do some casework for this one.
As you can see, we only have 4 options for this case.
+37146 
