Ms. smith is giving a test worth 100 points and contains 40 questions. there are two-point and four-point questions on the test.

Let x be the number of questions worth 2 points and y the number of questions worth 4 points.

X•2+y•4=100 points
X+ y=40 questions

X=40-y substitute in the first equation
(40-y)•2+4y=100
80-2y+4y=100
2y=100-80=20 so y=20/2=10
So x=40-10=30

There are 30 questions worth 2 points and
10 questions worth 4 points.

Verify 30•2+10•4= 60+40=100 ✔️