A store will increase the cost price of a certain garment by 50%, and then price it and sell it at a 20% discount. You can't make 20 yuan for anything.
The cost of solving and assuming is x yuan. According to the meaning of the question, it is:
( 1+50%)X*80%=20+X
1.2X=20+X
0.2X=20
X= 100
The cost of this piece is 100 yuan.