Time Speed and Distance

Puzzle-:

You have eight 8’s. Arrange all of them in any manner to give 1000 as the figure. (You can use addition , subtraction , multiplication and division). You can arrange 8’s horizontally , diagonally as well as vertically.

Concept-

1. Speed, Time and Distance:

Speed =

Distance ,Time

=

Distance , Distance = (Speed x Time).

Time Speed

2. km/hr to m/sec conversion:

x km/hr = x x5

m/sec.18

3. m/sec to km/hr conversion:

x m/sec = x x18

km/hr.5

4. If the ratio of the speeds of A and B is a : b, then the ratio of the

the times taken by then to cover the same distance is1

:1

or b : a.a b

5. Suppose a man covers a certain distance at x km/hr and an equal distance at ykm/hr. Then,

the average speed during the whole journey is2xy

km/hr.x + y

6. Downstream/Upstream:

In water, the direction along the stream is called downstream. And, the direction against the stream is called upstream.

7. If the speed of a boat in still water is u km/hr and the speed of the stream is vkm/hr, then:

Speed downstream = (u + v) km/hr.

Speed upstream = (u - v) km/hr.

8. If the speed downstream is a km/hr and the speed upstream is b km/hr, then:

Speed in still water =1(a + b) km/hr.

2Rate of stream

=1

(a - b) km/hr.2

Exercise-:

1. Ram crosses a 600 m long street in 5 minutes. What is his speed in km per hour?a. 7.2b. 3c. 4d. 5

2. An aeroplane covers a certain distance at a speed of 120 kmph in 5 hours. To cover the same distance in 5/3 hours, it must travel at a speed of:a. 360 kmphb. 720kmphc. 120kmphd. 400kmph

3. Ram 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. 20 kmb. 30 kmc. 40 kmd. 50 km

4. A train can travel 50% faster than a bus. Both start from point A at the same time and reach point B 75 kms away from A at the same time. On the way, however, the train lost about 12.5 minutes while stopping at the stations. The speed of the bus is:a. 100 kmphb. 110 kmphc. 120 kmphd. 130 kmph

5. In a flight of 600 km, an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by 200 km/hr and the time of flight increased by 30 minutes. The duration of the flight is:a. 1 hrb. 2 hrc. 3 hrd. 4 hr

6. Ram complete a journey in 10 hours. He travels first half of the journey at the rate of 21 km/hr and second half at the rate of 24 km/hr. Find the total journey in km.a. 220b. 224c. 226d. 228

7. A bus travelling with 5/7 of its actual speed covers 42 km in 1 hr 40 min 48 sec. Find the actual speed of the bus.a. 30 km/hb. 35 km/hc. 40 km/hd. 50 km/h

8. A boat running upstream takes 8 hours 48 minutes to cover a certain distance, while it takes 4 hours to cover the same distance running downstream. What is the ratio between the speed of the boat and speed of the water current respectively?a. 5:4b. 8:3c. 5:2d. 5:8

9. A boat takes 90 minutes less to travel 36 miles downstream than to travel the same distance upstream. If the speed of the boat in still water is 10 mph, the speed of the stream is:a. 2 mphb. 3 mphc. 4 mphd. 5 mph

10. A boatman goes 2 km against the current of the stream in 1 hour and goes 1 km along the current in 10 minutes. How long will it take to go 5 km in stationary water?a. 1 hrb. 2 hrc. 1 hr 15 mind. 1 hr 45 min

11. A journey of 192 km takes 2 hours less by a fast train than by a slow train. If the average speed of the slow train be 16 kmph less than that of fast train , what is the average speed of the fast train.a. 32 kmphb. 16 kmphc. 12 kmphd. 48 kmphe. 40 kmph

12. A passenger train takes 2 h less for a journey of 300 km if its speed is increased by 5 kmph over its usual speed. Find the usual speed.

a. 10 kmphb. 12 kmphc. 20 kmphd. 25 kmphe. 24 kmph

13. If Arun had walked 1 km/h faster , he would have taken 10 minutes less to walk 2 km. What is Arun’s speed of walking.a. 1 kmphb. 2 kmphc. 3 kmphd. 6 kmphe. None of these

14. A plane left half an hour later than the scheduled time and in order to reach irs destination 1500 km away in time, it had to increase its speed by 33.33 percent over its usual speed. Find its increased speed.a. 250 kmphb. 500 kmphc. 750 kmphd. 1000 kmphe. 1200 kmph

15. A train moves at a constant speed of 120 km/h for one km and at 40 kmph for the next one km. What is the average speed of the train.a. 48 kmphb. 50 kmphc. 80 kmphd. 60 kmphe. None of these

16. A cyclist moving on a circular track of radius 100 m completes one revolution in 2 minutes. What is the average speed of the cyclist (approx)?a. 314 m/minuteb. 200 m/minutec. 300 m/minuted. 900 m/minutee. None of these

17. A person travelled a distance of 200 km between two cities by a car covering the first quarter of a journey at a constant speed of 40km/h and remaining three quarters at a speed of x km/h. If the average speed of the person for the entire journey was 53.33 km/h , what is the value of x.a. 55 km/hb. 60 km/hc. 70 km/hd. 80 km/h

e. 100 km/h18. Walking at ¾ of his usual speed , a man is 16 minutes late for his office. The usual time

taken by him to cover that distance is a. 48 minb. 60 minc. 42 mind. 62 min e. 75 min

19. A and B travel the same distance at a rate of 8 km and 10 km an hour respectively. If A takes 30 min longer than B , the distance travelled by B is a. 6 km b. 10 kmc. 16 kmd. 20 km

20. Vinay runs 100 m in 20 sec and Ajay runs the same distance in 25 sec. By what distance will Vinay beat Ajay in a hundred metre race.a. 10 mb. 20 mc. 25 md. 12 m