Someone please help i can’t find the answer.

Autility company burns coal to generate electricity. the cost c(p), (in dollars) of removing p percent of the some stack pollutants is given by c(p)= 85000p/100-p a) find the cost to remove 30% of the pollutant b) find where the function is undefined

27 is what percent of 108? 27 is % of 108

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25