Answer:
Number of questions constraint:
x + y ≥ 15
Time constraint :
5x + 8y ≤ 120
Explanation:
Let :
x = number of equations
y = number of word problems
Number of answers required = atleast 15
Equation takes 5 minutes
Word problem takes 8 minutes
Time available to complete exam = 120 minutes
Constraints :
Number of questions required
Total questions shout be atleast 15
x + y ≥ 15
Time constraint :
5x + 8y ≤ 120