A company produces two articles, A and B. The per unit price of A is 25% less than the per unit price of B. By what percent is the sales (units) of A more than the sales of B if the revenue earned from A is 1.5 times the total revenue earned from B?
50%
75%
100%
125%
Step 1: Translate prices.
Let \(P_B\) be B's price and \(P_A=0.75P_B\) (25% less).
Step 2: Use the revenue relation.
Let \(Q_A,Q_B\) be units sold. Given revenue \(R_A=1.5R_B\):
\[ P_AQ_A = 1.5\,P_BQ_B \quad \Rightarrow \quad 0.75P_B\,Q_A = 1.5P_B\,Q_B. \] Cancel \(P_B > 0\): \(\ 0.75Q_A = 1.5Q_B \Rightarrow Q_A/Q_B = 2.\)
Step 3: Percent by which A's sales exceed B's.
\[ \frac{Q_A-Q_B}{Q_B}\times100 = \frac{2Q_B-Q_B}{Q_B}\times100 = 100\%. \] \[ \boxed{100\%} \]
At a college football game, $\tfrac{4}{5}$ of the lower-deck seats were sold. The lower deck contains $\tfrac{1}{4}$ of all stadium seats. Overall, $\tfrac{2}{3}$ of all stadium seats were sold. What fraction of the unsold seats in the stadium lay in the lower deck?