So this is going to be alot of writing to show my thinking but ill bold the answer.
1,1
1,2
1,3
1,4
1,5
2,1
2,2
2,3
2,4
2,5
3,1
3,2
3,3
3,4
3,5
4,1
4,2
4,3
4,4
4,5
5,1
5,2
5,3
5,4
5,5
next ill mark all the ones that equal 4 or 8 when added together, with an x
1,1
1,2
x1,3
1,4
1,5
2,1
x2,2
2,3
2,4
2,5
x3,1
3,2
3,3
3,4
x3,5
4,1
4,2
4,3
x4,4
4,5
5,1
5,2
x5,3
5,4
5,5
that is 6 (that equal 4 or 8) out of 25
so your ratio would be 6:19
The volume of the pyramid is 94.5
To get 20/10 as a mixed number you would have to take 20 and divide it by 10. Once you do that your answer should be 2.