A quiz had only 3-point questions and four-point questions. The best possible score is 100, and there are 29 questions. How many 4-point questions are there?

Answer 1

number of 4 point questions --- x
number of 3 point questions --- 29-x

solve for x

4x + 3(29-x) = 100

Answer 2

4x+3(29-x)=100
4x+87-3x=100
87+x=100
x=13
13 questions
:)