At a garage sale ,all of the prices of the items sold were different.If the price of a radio sold at

题目

At a garage sale ,all of the prices of the items sold were different.If the price of a radio sold at the garage sale was both the 15th highest price and the 20th lowest price among the prices of the items sold,how many items were sold at the garage sale
.答案是(34)

答案

This should be a problem for primary school students.
The key point is that the descending order was calculated by the subtraction of increasing orders plus one,since the last item should be ordered one rather zero in descending order.