It is1035km from Shanghai to Beijing. A train starts from Shanghai to Beijing with a journey of 185km and 2.5 hours. At this time, the second train leaves Beijing for Shanghai. Seven hours later, two trains met. How many kilometers per hour is the B train?

Solution: Train B runs every hour:

( 1035- 185)/7- 185/2.5

= 12 1.43-74

= 47.43 km/h

The distance between 3 A Town and B Town is138km. Zhang and Wang set out from the two towns at the same time and walked in opposite directions. Zhang's speed 13 km, Wang's speed 12 km, Wang's delay in driving 1 hour, and then continue driving. How many hours did it take from departure to meeting?

Solution: Time from departure to meeting:

138+12)/(13+12) = 6 hours.

It is estimated that it will take 40 minutes for a car to travel from A to B at a speed of 525 meters per minute. However, the machine broke down halfway and was repaired in 5 minutes. If we still arrive within the expected time, how many meters will the remaining distance be faster than the original speed per minute?

Solution:

(525*40)/2/(20-5)-525

= 10500/ 15-525

=700-525

=175m/min.