1, Xiaoming likes football. He learned that football is surrounded by black pentagons and white hexagons, and the number ratio of black and white leather blocks is 3:5. There are 32 pieces of leather on the surface of a football. Can you count the number of black leather and white leather?

2. Shooting practice.

(1) Xiaohua made 40 shots and hit 35 times. What's his hit rate?

(2) Xiaoming made only 3 of 30 shots. Do you know what his hit rate is?

3. As of June 2005 1 65438+1 October1day, the total population of China was1306.28 million, compared with the population at 0: 00 in 20001October/day. In terms of age, the population aged 60 and above accounts for about11%of the total population; In terms of gender, men account for a large proportion, accounting for about 5 1.5% of the total population.

(1) What was the proportion of the total population in 2005 compared with that in 2000?

(2) What is the proportion of the total population under 60?

(3) What is the percentage of women in the total population?

There are about 4,000 species of mammals in the world, and there are about 500 species in China. What percentage of mammals in China account for the total number of mammals in the world?

5. The hibernation time of snakes is generally 180 days, while that of frogs is 5/6 of that of snakes, and that of bears is 4/5 of that of frogs. How many days does the bear hibernate?

6. Legend has it that there was an old man in ancient India who left a will before he died: give 19 cows to his three sons, the big one to 1/2 and the small one to 1/5. How many cows did they get respectively?

7. March 22nd, 2006 is World Water Day. UNESCO published the World Water Resources Development Report, which informed the global water resources situation, among which the water pollution problem is very serious. In 2005, about 365,438+million people died of diarrhea and malaria due to water quality problems in the world, of which 9/ 10 were children under 5 years old. How many children under five died of diarrhea and malaria?

8. The surface area of the earth is about 500 million square kilometers, of which the land area is about 65.438+500 million square kilometers, and the rest is oceans.

(1) What percentage of the earth's surface area is the land area?

(2) What percentage of the earth's surface area does the ocean occupy?

9. The global land area is about 65.438+0.5 billion square kilometers, and there are currently 36 million square kilometers of desertified land. What is the percentage of desertification land in the global land area?

10, the per capita land area of the world 12/5 hectares, and the per capita land area of China is 2/3 less than that of the world. What is the per capita land area of China?

1 1. At present, the area of soil erosion in China is about 750,000 square kilometers, of which the area of soil erosion in the Yellow River basin accounts for 3/5. What is the area of soil erosion in the Yellow River Basin?

12. The total area of Taiwan Province Province is 3.6 million hectares. Forest resources are abundant, and the area of forestland accounts for 12/25 of the total area. What is the area of non-forest land in Taiwan Province Province?