An exam consists of two parts, Section X and Section Y. There can be a maximum of 80 questions. There must be at least 20 more questions in Section Y than in Section X. Write a system of inequalities to model the number of questions in each of the two sections. Then solve the system by graphing.

Answer 1

X + Y =< 80.
Y => x+20.

X + (X+20) =< 80.
2x+ 20 =< 80.
2x =< 80-20.
3x =< 60.
X =< 20.

Y => 20 + 20.
Y => 40.

Answer 2

12