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There are two ways for someone to go out from his place of residence, one is to go by bike, the other is to go by bus. Obviously, the speed of bus is faster than that of bicycle, but there is a waiting time (waiting time can be regarded as fixed). In any case, he always adopts the best way to spend the least time. The table on the next page shows that he arrives at a, B and C How long does it take for him to get to 8 kilometers away from his home? The best distance between the destination and the place of residence is a 2 km 12 min, B 3 km 15.5 min, C 4 km 18 min
According to the above analysis, we know that: to get to the place 8 km away from the place where we live, we should use the bus scheme. The time required for each kilometer of the bus line: 18-15.5 = 2.5 (minutes), waiting time: 18-2.5 × 4, = 18-10, = 8 (minutes), 8 + 2.5 × 8, = 8 + 20, = 28 (minutes). A: in order to get to the place 8 km away from the place where we live, it takes him 28 minutes
Xiaoming and Xiaoliang are 40km apart. Xiaoming starts for 1.5h, Xiaoliang starts again, Xiaoming is in the back, Xiaoliang is in the front, and they walk in the same direction
Xiao Ming's speed is 8 km / h, Xiao Liang's speed is 6 km / h. how many hours after Xiao Ming set out, did he catch up with Xiao Liang? Is it 14 hours or 15.5 hours
If we set out for X hours to catch up, there will be;
8x-6（x-1.5）=40;
8x-6x+9=40;
2x=31;
x=15.5;
So I started 15.5 hours to catch up;
15.5-1.5 = 14 hours is the departure time of vehicle B;
It's 15.5 hours since q a starts
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The distance between a and B is 40km. A starts for 1.5h and then B starts. A is behind and B is in front. They walk in the same direction. The speed of a is 8km / h and that of B is 6km / h. how many hours after a start, can a catch up with B?
Let a catch up with B after starting for X hours. From the meaning of the question: 8x-6 (x-1.5) = 40, the solution is x = 15.5. Answer: a catch up with B after starting for 15.5 hours
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