1. One day, Xiaoming was walking between home and school. Out of curiosity, he measured that the speed when there is no wind is 50 m/min. It took fifteen minutes to get from home to school, and it took 18 minutes and 20 seconds to return from the original road. How far is it from home to school?

1. Wang Qiang took part in the 3000m race. After running at a speed of 6m/s for a period of time, he ran the remaining distance at a speed of 4m/s, which took ten minutes. How many meters did Wang Qiang run at a speed of 6 meters per second?

7. Three classes in Grade One and Grade Three donate books to Hope Primary School. A class library 152 volumes. The number of books donated by Class Two is the average of three classes. The number of books donated by Class Three accounts for 40% of the total number of books donated by Class Three. How many books did Class Three donate?

1. The seventh-grade students of Yucai School walked to the Sun Yat-sen Mausoleum in the suburbs for a spring outing at a speed of 5 kilometers per hour. After walking for 48 minutes, the school had to send an urgent notice to the captain. The correspondent started from the school and chased the students at a speed of 35 km/h by motorcycle. How long did it take the correspondent to catch up with the students?

1. The social practice team of a school visited 100 families and found that the concentration of general washing water is 0.2%-0.5%, that is, it is more appropriate to contain 200-500g washing powder in 100kg washing water, because the surface activity is the largest and the decontamination effect is the best. At present, one washing cylinder can hold 15. It is known that the existing clothes in the tank weigh 4kg, and the required washing water concentration is 0.4%. Two spoonfuls of washing powder have been put in (1 spoon of washing powder is about 0.02kg). How many Jin of washing powder is needed and how much Jin of water is appropriate?

1. The flood control headquarters decided to turn on the pumps to drain water in the rain, assuming that the amount of rain increased every hour is the same, and the displacement of each pump is also the same. If one pump is turned on 10 hour and two pumps are turned on for three hours, how many hours does it take to turn on three pumps to discharge accumulated water?

1. When Party A and Party B climb the mountain, Party A climbs 10 meter every minute and starts for 30 minutes. B climbs 15 meters per minute, and both of them climb to the top of the mountain at the same time. How long does it take to climb this mountain? How high is this mountain?