1. | How many minutes does John take to cover a distance of 400 m, if he runs at a speed of 20 km/hr? |
---|---|

Solution: John’s speed = 20 km/hr = [20*5/18] m/sec= 50/9 m/sec. | |

2. | While covering a distance of 24 km, a man noticed that after walking for 1 hour and 40 minute, the distance covered by him was 5/7 of the remaining distance. What was his speed in metres per second? |

Solution: Let the speed be x km/hr.Then, distance covered in 1 hr: 40 min. i.e., 1 2/3 hrs = 5 x/3 km.Remaining distance = [24-5 x/3] km. ∴ 5x/3 = 5/7[24-5x/3] ⇔ 5x/3 = 5/7[72-5x/3] ⇔ 7x = 72-5x ⇔ 12x = 72 ⇔ x = 6Hence, speed = 6 km/hr = [6*5/18] m/sec = 5/3m/sec = 1 2/3 m/sec | |

3. | If a man walks at athe rate of 5 kmph, he misses a train by 7 minutes. However, if he walks at the rate of 6 kmph, he reaches the station 5 minutes before the arrival of the train. Find the distance covered by him to reach the station. |

Solution: Let the required distance be x km.Difference in the times taken at two speeds = 12 min = 1/5 hr. ∴ x/5 - x/6 = 1/5 ⇔ 6x - 5x = 6 ⇔ x = 6.Hence, the required distance is 6 km. |