There are three cars, a, B and C, each driving at a certain speed from a to B. B starts 10 minutes later than C and catches up with C 40 minutes later; a starts 20 minutes later than B and catches up with C 1 hour and 40 minutes later?

There are three cars, a, B and C, each driving at a certain speed from a to B. B starts 10 minutes later than C and catches up with C 40 minutes later; a starts 20 minutes later than B and catches up with C 1 hour and 40 minutes later?

The distance that C takes 130 minutes, B takes 130 × 4050 = 104 (minutes), suppose a takes X minutes, we can get: 100104 = XX + 20104x = 100 (x + 20), 104x = 100x + 2000, & nbsp; 4x = 2000, & nbsp; X = 500. A: it takes 500 minutes for a to catch up with B

A and B set out at the same time from a and B which are 180 km apart. A rides a bicycle and B rides a motorcycle. They travel at a constant speed along the same route. It is known that a's speed is 15 km / h and B's speed is 45 km / h. how long does it take for them to meet each other?

Let two people meet after X hours. From the meaning of the question: 15x + 45x = 180, the solution is: x = 3