申論題

3. In an imaginary economy, consumers buy only sandwiches and magazines. In 2016, the base year, a sandwich cost $5 and a magazine cost $4. The consumers bought 20 sandwiches and 25 magazines at these prices. In 2017, a sandwich cost $6.

(A)(8 points) If the consumer price index in 2017 was 125, then how much did a magazine cost in 2017?