A grasshopper tries to climb a slippery wall that is 3.4 m high. Every time the grasshopper jumps up 36 cm, it slides down 20 cm. What is the total number of jumps required for the grasshopper to reach the top of the wall?

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)?