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 earn 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.

The correct option is :

Lisa would earn $65 more than Mary.

Step-by-step explanation:

Let 'b' define base salary of Mary.

Let 'm' define the fee per student.

As per given information, Mary's expressions become:

For Monday:   .... (1)

For Tuesday:     ....(2)

Subtracting (2) from (1) to get the value of m

m = 4

b = 30

So, the complete equation that represents Mary's salary is :

For 20 students, the salary becomes:

= $110

Similarly, Lisa's earnings can be shown as :

So, for 20 students, Lisa's salary is :

= $175

-----------------------------------------------------------------------------------

Now difference between both girl's salary = dollars.

So, the correct option is :

Lisa would earn $65 more than Mary.

the correct option is 2.

step-by-step explanation:

according to the given information triangle abc is a right angle triangle with right angle at a. segment ab is 5 and segment ac is 7. point d is on segment bc and angles adb and adc are right angles.

it is given that triangles abd, cad, and cba are similar.

two triangles are similar if their corresponding sides are proportional.

in triangle cba, using pythagoras theorem

                      )

triangle abd and cba are similar,

                            (2)

triangle cad and cba are similar,

                      )

using (1), (2) and (3), we get

hence proved.

therefore option 2 is correct.