Set up a system of equations:
10x+2y=100
x+y=30
Isolate variable in one equation:
y=-x+30
Substitute in the variable:
10x+2(-x+30)=100
10x-2x+60=100
8x+60=100
8x=40
x=5
Substitute the x value back in:
x+y=30
5+y=30
y=25
There are 5 10-point questions and 25 2-point questions
Good luck!