(2006? Uncle Zhang, a vegetable farmer in Jiangyin, went to the market to sell his own 87 kg cucumber. For convenience, he brought some small change and sold it at the market price.

(1) Looking at the picture, you can know that Uncle Zhang has 10 yuan change; After sale, there is 68.5 yuan in hand;

(2)(50- 10)÷50

=40÷50

=0.8 (yuan)

A: Before the price reduction, the yellow melon was 0.8 yuan per kilogram;

(3)(68.5-50)÷(87-50)

= 18.5÷37

=0.5 yuan

A: After the price reduction, the cucumber is 0.5 yuan per kilogram.

So the answer is: 68.5.