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Yes, I will- 1. A plane flies in the two cities with a wind speed of 24 km / h. It takes 2 hours and 50 minutes to fly along the wind and 3 hours to fly against the wind. The speed of the ball seamless aircraft is the same as the distance between the two cities 2. It takes 3 hours for a ship to go back and forth between wharf A and wharf B. It takes 30 minutes more for a ship to sail upstream than downstream. If the speed of the ship in still water is 26 km / h, calculate the current speed 3. A ship sails downstream from wharf a to wharf B, and then reverses to wharf C for 9 hours. It is known that the speed of the ship in still water is 7.5 km / h, and the water flow speed is 2.5 km / h. If the distance between wharf A and wharf C is 15 km, the distance between wharf A and wharf B is calculated Find the answers to these three questions I hope I can finish it by the end of the evening
1. The speed of the plane is v km / h. The distance between the two places is s km
S / (V + 24) = 170 (min)
S/(V-24)=180
17(V+24)=18(v-24)
V = 24 × 35 = 840 (km / h)
S = 170 (V + 24) = 170 × 24 × 36 / 60 = 2448 (km)
2. If the current velocity is x km / h, the time of sailing against the water is 3 hours and 30 minutes = 3.5 hours. The distance between wharf A and wharf B is 3 (x + 26) km, which is also expressed as 3.5 (26-x) km
3(x+26)=3.5(26-x)
3x+78=91-3.5x
3x+3.5x=91-78
6.5x=13
x=2
A: the water velocity is 2 km / h
3. Let the time from a to B be t, then the time from B to C is (9-t). The speed of downstream flow is 10km / h, and that of upstream flow is 5km / h. therefore, according to the meaning of the title, we can get 10t-5 (9-t) = 15, t = 4, and the distance of AB is 4 * 10 = 40km
Practice a lot, wish children's shoes study happy
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