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)