Answer:
$27
Step-by-step explanation:
18 times $1.50 = 27 dollars a year
So we solve for each
70% of 100=70
students who didn't buy lunch=100-70=30
some of the 70 left so that the students who bought lunch, are 60% of those who are left
we know that the students who didn't buy lunch didn't change number so therefor
100% of students left-60%=40%= students that didn't buy lunch=30 so
40%=30
20%=15
100%=75
there were 75 students lfet in the cafeteria