Answer :
Lowering the price : $100 - $100 x 20/100 = $100 - $20 = $80
Raising the price: $80 + $80 x 20/100 = $80 + $16 = $96
Final price: $96
Raising the price: $80 + $80 x 20/100 = $80 + $16 = $96
Final price: $96