Lissete bought a new pair of earrings on sale for 20% off the original cost if the original cost was $30 how much did she pay for the earrings on sale

Cost of the earrings on sale=original cost-20% of the original cost.

Data:
origninal cost=$30
20%=20/100=0.2

Cost of the earrings on sale=$30-(0.2)($30)
=$30-$6
=$24

she paid $24 for the earrings on sale.

The first option would be correct if it were one half and not one