Mathematics Part i Solutions Solutions for Class 7 Math Chapter 6 Speed...More Speed are provided here with simple step-by-step explanations. These solutions for Speed...More Speed are extremely popular among class 7 students for Math Speed...More Speed Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Mathematics Part i Solutions Book of class 7 Math Chapter 6 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Mathematics Part i Solutions Solutions. All Mathematics Part i Solutions Solutions for class 7 Math are prepared by experts and are 100% accurate.
Page No 72:
Question 1:
Anil and Alex are car drivers. Anil drove 180 kilometers in 4 hours and Alex drove 230 kilometers in 5 hours. Whose average speed is greater?
Answer:
Distance travelled by Anil in 4 hours = 180 km
We know that
So, speed of Anil’s car = km/h
= 45 km/h
Distance travelled by Alex in 5 hours = 230 km
So, speed of Alex’s car = km/h
= 46 km/h
The average speed of Alex’s car is greater than the average speed of Anil’s car.
Page No 73:
Question 1:
Can complete this table.
Distance travelled |
Time taken |
Average speed |
150 km |
5 hours |
.................... |
360 km |
4 hours 30 minutes |
.................... |
.................... |
12 hours |
52 km/hour |
.................... |
8 hours 30 minutes |
54 km/hour |
600 km |
.................... |
30 km/hour |
475 km |
.................... |
50 km/hour |
.................... |
2 hours 15 minutes |
60 km/hour |
Answer:
We know that
Distance travelled |
Time taken |
Average speed |
150 km |
5 hours |
|
360 km |
4 hours 30 minutes = |
|
(52 × 12) km = 624 km |
12 hours |
52 km/h |
8 hours 30 minutes = |
54 km/h |
|
600 km |
30 km/h |
|
475 km |
50 km/h |
|
2 hours 15 minutes = |
60 km/h |
Note: 60 minutes = 1 hour
Page No 73:
Question 2:
Sabu got into the bus at 6 o’clock. Usually the bus travels at an average speed of 30 km/hr and reaches the railway station at ten. But that day, it was raining and it could manage only an average speed of 20 km/hr. Sabu got down from the bus at eight and caught a car. He reached the station at ten itself. What was the average speed of the car?
Answer:
Usual average speed of the bus = 30 km/h
Time taken by the bus to reach the railway station = 4 hours (from 6 o’clock to 10 o’clock)
We know that distance travelled = Average speed × time taken
∴ Distance covered by the bus = (30 × 4) km = 120 km
On the rainy day, the average speed of the bus = 20 km/h
Time taken by the bus = 2 hours (from 6 o’clock to 8 o’clock)
∴ Distance covered by the bus in 2 hours = (20 × 2) km = 40 km
Remaining distance covered by the car in 2 hours (from 8 o’clock to 10 o’clock)
= 120 km − 40 km
= 80 km
Thus, average speed of the car
=
= km/h
= 40 km/h
Page No 77:
Question 1:
Vipin cycled to his friend’s house, travelling at an average speed of 10 km/hr and then back home at an average speed of 15 km/hr. What is the average speed of the entire ride?
Answer:
Let the distance travelled by Vipin between his house and his friend’s house be x km.
Total distance travelled by Vipin = (x + x) km = 2x km
We know that time taken =
Time taken by Vipin to reach his friend’s house = hours
Time taken by Vipin to return home = hours
Total time taken by Vipin = hours
= hours
= hours
= hours
= hours
∴ Average speed during the entire ride =
= km/h
= 12 km/h
Page No 77:
Question 2:
Now can’t you complete this table
km/hour |
72 |
48 |
1 |
…….. |
……. |
metre/second |
…….. |
…….. |
…….. |
1 |
20 |
Answer:
We know that 1 km = 1000 m
1 hour = (60 × 60) seconds = 3600 seconds
km/hour |
72 |
48 |
1 |
||
metre/ second |
1 |
20 |
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