Speed Distance and Time Class 7 RS Aggarwal Exe-12A Goyal Brothers ICSE Foundation Maths Solutions

Speed Distance and Time Class 7 RS Aggarwal Exe-12A Goyal Brothers ICSE Foundation Maths Solutions. We provide step by step Solutions of lesson/ Chapter-12 Speed Distance and Time for ICSE Class-7 Foundation RS Aggarwal Mathematics of Goyal Brothers Prakashan to develop skill and confidence. Visit official Website CISCE for detail information about ICSE Board Class-7 Mathematics.

Speed Distance and Time Class 7 RS Aggarwal Exe-12A Goyal Brothers ICSE Foundation Maths Solutions

Board	ICSE
Publications	Goyal brothers Prakashan
Subject	Maths
Class	7th
Chapter-12	Speed Distance and Time
Writer	RS Aggrawal
Book Name	Foundation
Topics	Solution of Exe-12A
Academic Session	2024 – 2025

Speed Distance and Time Exe-12A

Class 7 RS Aggarwal Goyal Brothers ICSE Foundation Maths Solutions

Page-146

Que-1: Convert each of the following speeds into m/sec: (i) 90 km/hr  (ii) 27 km/hr  (iii) 315 km/hr  (iv) 16.2 km/hr

Ans- (i) 90 km/hr = 90 km / 1 hr

=> 90 x 1000 / 1 x 60 x 60 = 25 m/s

  (ii) 27 km/hr =  27 km / 1 hr

=> 27 x 1000 / 1 x 60 x 60 = 7.5 m/s

  (iii) 315 km/hr = 315 km / 1 hr

=> 315 x 1000 / 1 x 60 x 60 = 87.5 m/s

  (iv) 16.2 km/hr = 16.2 km / 1 hr

=> 16.2 x 1000 / 1 x 60 x 60 = 4.5 m/s

Que-2: Convert each of the following speeds into km/hr: (i) 35 m/sec  (ii) 14 m/sec  (iii) 60 m/sec  (iv) 3.5 m/sec

Ans- (i) 35 m/sec 

=> 35 x 60 x 60 / 1000 = 126 km/hr

(ii) 14 m/sec 

=> 14 x 60 x 60 / 1000 =  50.4 km/hr

(iii) 60 m/sec 

=> 60 x 3600 / 1000 = 216 km/hr

(iv) 3.5 m/sec

=> 35 x 60 x 60 / 1000 = 12.6 km/hr

Que-3: A car travels a distance of 258 km in 3 hours 35 minutes. What is the speed of the car?

Ans- Distance = 258 km

time = 3 hour 35 min = (3 + 35/60) hr = 43 / 12

Speed = Distance / time

=> 258 x 12 / 43 = 72 km/hr

Que-4: A train covers 14 km in 8 minutes. What is the speed of the train?

Ans- Distance = 14 km

time = 8 min = (8/60) hr = 2/15 hr

Speed = Distance / time

=> 14/2 x 15 = 105 km/hr

Que-5: A man can walk 8 km in 1 hour 15 minutes. Find his speed.

Ans- Distance = 8 km

time = 1 hour 15 min = (1 + 15/60) hr = 5 / 4

Speed = Distance / time

=> 8 x 4 / 5 = 6.4 km/hr

Que-6: Rahul cycles at 12 km per hour. How much distance does he cover in 36 minutes?

Ans- Speed = 12 km/hr

time = 36 min = 30/60 hr = 3/5 hr

Distance = Speed x time

= 12 x 3/5 = 36/5 = 7.2 km

Que-7:  Ravi walks at a uniform speed of 4 km per hour. How much time does he take to cover 600 metres?

Ans- Speed = 4 km/hr

Distance = 600 m = 600/1000 = 3/5 km

time = distance / speed

=> (3 x 60) / (5 x 4) = 9 min

Que-8: A train is running at 45 km per hour. How far does it go in 8 seconds?

Ans- Speed = 45 km/hr = 45 x 1000 / 60 x 60 = 25/2 m/s

The train travel in 1 sec = 25/2 m

It will travel in 8 sec = 25/2 x 8 = 100 m

Que-9: Which is more a speed of 36 km/hr or a speed of 10.5 m/sec?

Ans- Speed = 36 km/hr = 36 x 1000 / 60 x 60 = 10 m/s

10 m/s is less than 10.5 m

10.5 m/s is more than 36 km/hr

Que-10: A car, running at 45 km/hr takes 6 hours to cover a journey. At what speed must it travel to complete the journey in 5 hours?

Ans- Speed = 45 km/hr

time = 6 hr

distance = 45 x 6 = 270 km

time = 5 hrs

distance = 270 km

new speed = distance/time

=>270 / 5 = 54 km/hr

Que-11: A car covers a certain distance in 50 minutes if it runs at 45 km per hour. How much time will it take to cover the same distance at a speed of 30 km per hour?

Ans- Speed = 45 km/hr

time = 50 min = 50/60 = 5/6 hr

distance = speed x time

=> 45 x 5/6 = 37.5

now, speed = 30 km/hr

distance = 37.5 km

time = distance / speed

=> 37.5 x 60 / 30 = 75 min = 1 hour 15 min

Que-12:  A bus covers 100 km in first 2 hours, 64 km in the next 1 hour and 72 km in the next 2 hours. Find the average speed of the bus during the whole journey.

Ans- Total distance covered = (100 + 64 + 72) = 236 km

time = (2 + 1 + 2) = 5 hr

speed = distance / time = 236 / 5 km/hr

=> 47.2 km/hr

Que-13: An aeroplane covers 2500 km, 1200 km and 500 km at the rate of 500 km/hr, 400 km/hr and 250 km/hr respectively. Find its average speed for the whole journey.

Ans- Distance = 2500 km

Speed = 500 km/hr

time = 2500 / 500 = 5 hr

Distance = 1200 km

Speed = 400 km/hr

time = 1200 / 400 = 3 hr

Distance = 500 km

Speed = 250 km/hr

time = 500 / 250 = 2 hr

Total Distance = (2500 + 1200 + 500) km

Total time = 2 + 5 + 3 = 10 hr

Speed = Distance / Time

=> 4200 / 10 = 420 km/hr

Que-14: A scooterist travels at 36 km/hr for 5 hours and at 45 km/hr for 4 hours. Find his average speed for the whole journey.

Ans- Speed = 36 km/hr

time = 5hr

Distance = 180 km

II Speed = 45 km/hr

time = 4 hr

Distance = 45 x 4 km = 180 km

Total time = 5 + 4 = 9 hr

Total Distance = 180 + 180 km = 360 km

Speed = Distance/Time = 360 / 9 = 40 km/hr

Que-15: Raju’s school is 4 km away from his house. He walks from his house to school and comes back in 2(1/2) hours. Find his average speed.

Ans- Distance = (4 + 4) km = 8 km

Total time = 2(1/2) = 5/2 hr

Speed = Distance / time

=> 8 x 2 / 5 = 3.2 km/hr

Que-16: Find the time taken by a train 150 m long, running at 60 km/hr in crossing a man standing on the platform.

Ans- Speed = 60 km/hr

length of train = 150 m

Distance = 150 m = 150 / 1000 = 0.15 km

time to cross the man = distance/time

=> 0.15/60 = 15 x 60 / 100 x 60 = 9 sec 

Que-17: The length of a train is 175 m. It is running at 63 km/hr. In how much time would it cross an electric pole?

Ans- length of train = 17 m

Speed = 63 km/hr

Distance = 175 m = 175 / 1000 km

Time = Distance / Speed = 175 x 60 x 60 / 1000 x 63 = 10 s

Que-18: A train 150 m long crosses a tree in 6 seconds. What is the speed of the train in km per hour?

Ans- Distance = 150 m

time = 6 s

Speed = Distance / time

=> 150 x 60 x 60 / 6 x 1000 = 90 km/hr

Que-19: A train 120 m long is running at 54 km per hour. In how much time will it pass a bridge 180 m long?

Ans- Speed 54 km/hr

Distance = (120 + 180) = 300 m = 300 / 1000 = 3/10 km

time = 3 x 60 x 60 / 10 x 54 = 20 s

Que-20: A train 760 m long crosses a platform 440 m long in 40 seconds. Find the speed of the train in km per hour.

Ans- Distance = (760 + 440) = 1200 m = 1200/1000 = 12/10 km

time = 40 s = 40 / 60 x 60 = hr

Speed = 12 x 60 x 60 / 10 x 40 = 108 km/hr

— : End of Speed Distance and Time Class 7 RS Aggarwal Exe-12A Goyal Brothers ICSE Foundation Maths Solutions :–

Return to : – ICSE Class -7 RS Aggarwal Goyal Brothers Math Solutions

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