Ishaan has to reach Kolkata which is 737 km away in 21 hours. His starting speed for 7 hours was 49 km/hr. For the next 184 km his speed was 46 km/hr. By what speed must he travel now so as to reach Kolkata in the decided time of 21 hours?
21 km/hr
The distance covered in 7 hours = 49 × 7 = 343 km. The distance covered in the next 184 km is fixed. The remaining distance = 737 - (343 + 184) = 210 km. Time remaining = 21 - 7 - (184 / 46) = 21 - 7 - 4 = 10 hours. Speed required = 210 / 10 = 21 km/hr.
Important Questions from Speed Time and Distance
A train travelling at a speed of 72 km/hr crosses a post in 20 seconds. If it crosses another train travelling at a speed of 54 km/hr in the same direction in 1 minute 45 seconds, then the difference in length between the two trains is
Rajiv's boat can travel along the current at the 8 km/hour and against the current at the rate 6 km/hour. Find the time taken by the boat to sail 28 km in still water.
Rohit and Dinesh are 64 km apart. Rohit can walk at a speed of 15 km/hr and Dinesh at the speed of 17 km/hr. In how many hours will they meet if they are travelling towards each other?
Two trains running in opposite directions cross a man standing on the platform in 25 seconds and 32 seconds respectively and they cross each other in 30 seconds. The ratio of their speed is:
A worker covers a distance of 81 km in 11 hours. He travels partly on foot at 4.5 km/h and partly on bicycle at 15 km/h. What is the distance covered on the cycle?
