Mountainous area:10 * 71%= 7.1(square kilometers) =7 1000 (square kilometers) Plain: 10*23%=2.3 (square kilometers) =23000.

I want to say that Zhejiang Province has very little water resources, so we should save them.

Total number of medals: 63÷52%≈ 12 1.

How many silver medals are there? 12 1*28%=34 (pieces)

Pass (25)% excellent (30)% good (16) 2 people failed, a total of 40 people.