To estimate the sale price of the bathing suit at 50% off regular price, it is only necessary to calculate the 50% of $89.99.
You proceed as follow:
(50/100)(89.99) = 44.99
that is, to calculate the 50% you calculate the product between 50 divided by 100 and the reglar price 89.99.
Hence, the sale price of the bathing suit at 50% off regular price is $49.99