Mrs. Wise bought 3 lb of apples at $4 per lb. The next day, apples were on sale for "20% off" so she bought another 5 lb. What was the average price for all the apples she bought?

Mrs Wise first bought 3lb (4$) for a total of 12 dollars

Mrs Wise then bought 5lb (4$) for a total of 20 dollars but with the percent off saved 4 dollars (.20 x 20)

Because of this Mrs Wise bought all of the apples for approximately 28$ (12+16)