x+y=24
3x + 5y = 100
Rewrite the first equation: x = 24-y
Replace x in the second equation and solve:
3(24-y) +5y = 100
72-3y +5y = 100
72 +2y = 100
2y = 28
y = 14
Y is the number of 5 point questions, so there are 14 5 point questions.
The answer would be:
The test contains 10 three-point questions and 14 five-point questions.