Mr. Wilk's salary for 180 days = $33,660
Mr. Wilk's salary for 1 day = $?
By unitary method:
Days Salary
180 $33,660
1 ?
By cross-multiplication:
1*33660/180
33660/180 = $187
Mr. Wilk's salary per day = $187
Substitute teacher's salary per day = $85
Difference in salary = 187-85
= $102
The school district pays $102 less to the substitute teacher.