Aset of pencils sells for $1.75 and costs $0.40 to make. twenty percent of the profit(the difference between the purchase price and the amount it costs to make) from each set of pencils goes to the school. if 500 sets are sold. what is the amount of money that will go to the schools?

A set of pencils sells for 1.75 and costs 0.40 to make

if 500 sets are sold...
500(1.75) = 875...this is revenue
500(0.40) = 200this is expenses

profit = revenue - expenses
profit = 875 - 200
profit = 675

20% of the profit goes to the school...
0.20(675) = $ 135 <=== this is what goes to the school

0.12038674820353... 

0.15739205957493...

0.10683820485738...

and 

0.19359638695495...