A method to know the probability is to list down all of the possible combinations that would present an outcome of not more than 5. This is listed below:
1 + 4
4 + 1
2 + 3
3 + 2
1 + 1
2 + 2
1 + 2
2 + 1
1 + 3
3 + 1
There are 10 possible outcomes. But among these, the only ones that can have a sum more than 3 are:
1 + 4
4 + 1
2 + 3
3 + 2
2 + 2
1 + 3
3 + 1
There are only 7 possible outcomes that meet both requirements. Given that there are 7 outcomes within the total of 10, the probability would be 7/10, or 0.7.