Time and Distance BY: MAYANK AGNIHOTR

SOME BASIC FORMULAS Speed = 1 minute 60 seconds, 1 hour 60 min, 1 day 24 hrs, x am + 12 hr- x pm &viseversa xkm/hr - (xx 5) m/sec x m/sec = ( 10) Km/hr Tune = Distance Speed ' Distance Distance = Speed Time Time, 18 If ratios of speeds of A and B is a : b, then the ratio of times taken by them to cover the same distance is orb: a Suppose a man covers a certain distance at speed x km/hr and an equal distance at y km/hr. Then the average speed during the whole journey is )km/h

QUESTIONS Ques1. A person crosses a 600 m long street in 5 minutes. What is his speed in km per hour? Sol. Time = 5 min = 5 x60 sec = 300sec Speed = 600 2 m/sec now 2x7.2 km/hr Ans 18 Ques 2. A train leaves station at 6 14 am and reaches its destination after 13 hours 48 minutes. The time at the station is (a) 8:12 pm (b) 7:02 pm (c) 7:12 pm (d) 8:02 pm So 6am 13 hr 7 pm & 14 min + 48 min 62 min 1 hr 2 min therefore time at station is 8:02 pm

Ques 3. A train leaves station P at 8:18 am and reaches station Q at 10:28 pm on the same day. Find time taken by train to reach Q Sol. 8 am 12 hr 8 pm & 8 pm 2 hr 10 pm therefore total 12 +2 14 hr Also 18 min 10 min 28 min Therefore total time taken 14hr 10 min. Ans Ques 4. If a person walks at 14 km/hr instead of 10 km/hr, he would have walked 20 km more. The actual distance travelled by him is: A. 50 km B. 56 km . 70 km D. 80 km So Let the actual distance travelled be x km Then, * +20 10 14 14x = 10x + 200 4x = 200 x = 50 km.

Ques 5. Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour? Sol. 54 km in one hr with out stoppage & 45 km in one hr with stoppages Less distance cover due to stopages = 54-45 = 9 km Time taken to cover 9 km = hr = 60 min = 10 min Ans 9 54 9 54 The ratio between the speeds of two trains is 7 : 8. If the second train runs 400 km in 4 hours, then find the speed of the first train. Ques 6. So Let the speed of two trains be 7x and 8x km/hr 400 Then, 8x = 100 = = 100 = 12.5 :. Speed of first train = (7 12.5) km/hr = 87.5 km/hr.

Ques 7. Number of seconds in 6 hours is equal to the number of minutes in (a) 10 days (b) 12 days (c) 15 days 6 hr = 6 x 60 min = 6 x 60 x 60 sec = 21600 sec 1 day = 24 hr = 24 x 60 min = 1440 min (d) 16 days Sol. Now 1440 min 1 day21600 minx 21600 days - 15 days Ans

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Mayank Agnihotri

B.Tech (ECE), Machine enthusiast, Inspired by an old hindi saying " Gyan baatne se badhta ha"

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Shiyas

6 months ago

well done...

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