Question 950555
p for how many PUPILS, or students, initially planned.
p-8 actually did go on the trip.


{{{80/p}}} dollars per student was the needed PRICE to pay for the bus.


Now 0.50 dollar per student MORE must be paid from p-8 students.
New price is {{{(80/p+0.5)}}};
How many students now, {{{p-8}}};
Same COST as before.


{{{highlight((80/p+0.5)(p-8)=80)}}}.
When this equation and analysis leading to it make sense, then that is the help you needed.  (Solve for p, and then evaluate p-8).