Answer:
since lisa earns half of what mary does divide 62 into 2 which is 31
and she has 8 students.
she is paid twice as much in students, so lisa would earn more due to getting paid more with having more students, as she gets paid twice the amount from students she has, and if she had 20 she would get paid 40 but if you add 2x of the mass it will be 80, and mary will have 40.
if its incorrect i apologize.