Math
posted by Vince .
At Harry's Discount Hardware everything is sold for 20% less than the price marked. If Harry buys tool kits for $80, what price should he mark them if he wants to make a 20% profit on his cost?

0.8x = 80
x = 80/0.8
x = 100 >> selling price
0.8x = 100
x = 100/0.8
x = 125 >> marked price 
Ok, another solution for this problem:
20% of $80=16
so, the selling price=80+16=$96
Let, by the mark price of 20% profit=x
so, x(20% of x)=96
or, xx/5=96
or, x= (96*5)/4
or, x=$120 (Ans) 
the selling price is 80% of the marked price (m.p.)
moving on to the latter part of the question which states that 20% on $80 tools is Harry's profit. Making a profit of $16.So the selling price results to $96. Therefore,80% of m.p.=96.00 Solving this equation gives you m.p.=$120, which is your final answer