Worksheet Solutions: Time Speed & Distance | Mental Mathematics for Class 8 PDF Download

Q1: The average speed of a train in the onward journey is 25% more than that in the return journey. The train halts for one hour on reaching the destination. The total time taken for the complete to and fro journey is 17 hours, covering a distance of 800 km. The speed of the train in the onward journey is:
(a) 45 km/hr
(b) 47.5 km/hr
(c) 52 km/hr
(d) 56.25 km/hr
Ans: (d)

Q2: A, B and C are on a trip by a car. A drives during the first hour at an average speed of 50 km / hr. B drives during the next 2 hours at an average speed of 48 km / hr. C drives for the next 3 hours at an average speed of 52 km / hr. They reached their destination after exactly 6 hours. Their mean speed was:
(a) 50 km/hr
(b)  
(c)  
(d) 52 km/hr
Ans: (b)

Q3: A boy rides his bicycle 10 km at an average speed of 12 km/hr and again travels 12 km at an average speed of 10 km/hr. His average speed for the entire trip is approximately:
(a) 10.4 km/hr
(b) 10.8 km/hr
(c) 11 km/hr
(d) 12.2 km/hr
Ans: (b)

Q4: A car travels the first one-third of a certain distance with a speed of 10 km / hr, the next one-third distance with a speed of 20 km / hr, and the last one-third distance with a speed of 60 km / hr. The average speed of the car for the whole journey is:
(a) 18 km/hr  
(b) 24 km/hr    
(c) 30 km/hr    
(d) 36 km/hr
Ans: (a)

Q5: A car travelling with 5/7 of its actual speed covers 42 km in 1 hr 40 min 48 sec. Find the actual speed of the car. 
(a)
(b) 25 km/hr
(c) 30 km/hr
(d) 35 km / hr
Ans: (d)

Q6: Walking  6/7 th of his usual speed, a man is 12 minutes too late. The usual time taken by him to cover that distance is:
(a) 1 hour
(b) 1 hr 12 min
(c) 1 hr 15 min
(d) 1 hr 20 min
Ans: (b)

Q7: A train when moves at an average speed of 40 kmph, reaches its destination on time. When its average speed becomes 35 kmph, then it reaches its destination 15 minutes late. Find the length of journey.
(a) 30 km
(b) 40 km
(c) 70 km
(d) 80 km
Ans: (c)

Q8: If a train runs at 40 kmph, it reaches its destination late by 11 minutes but if it runs at 50 kmph, it is late by 5 minutes only. The correct time for the train to complete its journey is :
(a) 13 min
(b) 15 min
(c) 19 min
(d) 21 min
Ans: (c)

Q9: I started on my bicycle at 7 a.m. to reach a certain place. After going a certain distance, my bicycle went out of order. Consequently, I rested for 35 minutes and came back to my house walking all the way. I reached my house at 1 p.m. If my cycling speed is 10 kmph and my walking speed is 1 kmph, then on my bicycle I covered a distance of:
(a)       
(b)       
(c)      
(d)  
Ans: (a)

Q10: A man on tour travels first 160 km at 64 km/hr and the next 160 km at 80 km /hr. The average speed for the first 320 km of the tour is:
(a) 35.55 km/hr
(b) 36 km/hr
(c) 71.11 km/hr
(d) 71 km/hr
Ans: (c)

Q11: A man travels 600 km by train at 80 km/hr, 800 km by ship at 40 km/hr, 500 km by aeroplane at 400 km / hr and 100 km by car at 50 km / hr. What is the average speed for the entire distance ?
(a) 60 km/hr
(b)  
(c) 62 km/hr
(d)  
Ans: (d)

Q12: Mary jogs 9 km at a speed of 6 km per hour. At what speed would she need to jog during the next 1.5 hours to have an average of 9 km per hour for the entire jogging session ?
(a) 9 kmph
(b) 10 kmph
(c) 12 kmph
(d) 14 kmph
Ans: (c)

Q13: A train running at 7/11 of its own speed reached a place in 22 hours. How much time could be saved if the train would have run at its own speed ?
(a) 7 hours
(b) 8 hours
(c) 14 hours
(d) 16 hours
Ans: (b)

Q14: Starting from his house one day, a student walks at a speed of and reaches his school 6 minutes late. Next day he increases his speed by 1 kmph and reaches the school 6 minutes early. How far is the school from his house ?
(a) 1 km
(b)         
(c)
(d) 2 km
Ans: (c)

Q15: Robert is travelling on his cycle and has calculated to reach point A at 2 P.M. if he travels at 10 kmph; he will reach there at 12 noon if he travels at 15 kmph. At what speed must he travel to reach A at 1 P.M. ?
(a) 8 kmph
(b) 11 kmph
(c) 12 kmph
(d) 14 kmph
Ans: (c)