The local skating rink pays Mary a fixed rate per pupil plus a base amount to work as a skating instructor. She earns $90 for
instructing 15 students on Monday afternoon. Last Friday, she earned $62 for working with 8 students. Lisa is also a skating
instructor. She receives half the base amount that Mary does, but she is paid twice as much per student. Who would eam
more money instructing a class of 20 students?
Lisa would earn $120 more than Mary.
Lisa would earn $65 more than Mary.
Mary would earn $15 more than Lisa.
Mary would earn $10 more than Lisa.
Mark this and return
Save and Exit
Next
Submit
Who earns

The expressions for the payment made to Mary are,

        (Monday)      90 = 15m + b

        (Tuesday)     62 = 8m + b

where m and b are the fee per student and the base fee, respectively. Solving for m and b, the values are 4 and 30.

The equation that represents Mary's earning is

                                   y = 4x + 30

For 20 students,

                                   y = 4(20) + 30 = 110

For Lisa's earnings,

                                    y = 8x + 15

Substituting 20,

                                   y  =8(20) + 15 = 175

Thus, Lisa would earn more than Mary by $65.

Read more on -

Step-by-step explanation:

17 1/3

step-by-step explanation: