Speed sum (480-165) ÷ 9 = 35km/h.
Passenger ship speed 35× 4/(4+3) = 20km/h.
Cargo speed 35× 3/(4+3) = 15km/h
(2) Last year, Southeast Asia was hit by a tsunami, which caused great losses to people's lives and property. Xinying Middle School actively raises money and offers love. There are 50 students in one class who donate money, among which the class cadres donate 8 yuan on average and other students donate 5 yuan on average. * * * received 265 yuan and asked how many class cadres there were.
(265-5×50)÷(8-5)=5 people
(3) A cylindrical barrel with a bottom radius of 20 cm and a water depth of 80 cm is placed in it. Firstly, a cone-shaped iron block with a bottom circumference of 62.8 cm is soaked in a bucket, and the water surface is raised by one sixteenth to find the height of the cone-shaped iron block.
The radius of the cone bottom is 62.8 ÷ 3.14 ÷ 2 =10cm.
3. 14 * 20 * 20 * 80 * 1/ 16÷( 1/3 * 3. 14 * 10 * 10)= 60cm。
(4) The bus runs every 5 minutes from Station A to bilibili, and the whole journey takes 15 minutes. Someone rode a bike from bilibili to Station A. At the beginning, a car just started, and on the way, I met 10. When he arrived at Station A, another car was about to start. How long has this man been gone?
5×( 10- 15/5)=35 points.