2019 AMC 8 Problem 22

A store increased the original price of a shirt by a certain percent and then decreased the new price by the same amount. Given that the resulting price was 84\% of the original price, by what percent was the price increased and decreased?

\textbf{(A) }16\qquad\textbf{(B) }20\qquad\textbf{(C) }28\qquad\textbf{(D) }36\qquad\textbf{(E) }40

Full credit goes to MAA for authoring these problems. These problems were taken on the AOPS website.