The price of a product is reduced by 10% during the promotion period, and then increased by 10% after the promotion. At this time, the price of the product is lower than the original price () A. Unchanged B. reduced C. increased D. unable to judge
(1-10%) × (1 + 10%), = 0.9 × 1.1, = 99%, 99% < 1, so the current price is lower than the original price