An electrical lineman needs to climb a pole of height 50 meters. In the first minute, he climbs up 5 meters, and in the second minute, he slips down by 2 meters. He repeats this alternating process until he reaches the top of the pole. At what height was he at the end of the 24th minute?

Rohan walks around a circular field at the rate of 1 round per hour while Shreyas runs around it at the rate of 5 rounds per hour. They start in the same direction from the same point at 8:30 AM. When will they first cross each other?

In covering 90 km, R takes 4 hours more than S. If R triples his speed, then he would take 2 hours less than S. What is R's original speed (in km/h)?