On a 100 km road, a bus travels the first 30 km h¯¹
at a uniform speed of 30 km h . How fast must
the bus travel the next 70 km so as to average
50 km h¯¹ for the entire trip?
Answers
Answer :
- The bus should travel the next 70 km distance at a speed of 70 km h¯¹.
Given:
- On a 100 km road, a bus travels the first 30 km h¯¹ at a uniform speed of 30 km h¯¹.
- The bus travel the next 70 km so as to average 50 km h¯¹ for the entire trip.
To find :
- How fast must the bus travel the next 70 km so as to average 50 km h¯¹ for the entire trip = ?
Step-by-step explanation :
Speed = Distance travelled / Time taken
Total time taken = Total distance travelled /Average Speed
= 100/50 = 2 hours
We will now calculate the timw taken by the bus to travel the first 30 km and then calculate for next 70 km.
Speed = 30 km h¯¹
Distance = 30 km
Time = ?
Speed = Distance travelled / Time taken
∴ Time = Distance /Speed
= 30/30 = 1 hour
For the second part of the bus journey, let us suppose that the speed of a bus is x km h¯¹. So for second part of the bus journey,
Speed = x km h¯¹
Distance = 70 km
Time =?
Speed = Distance travelled / Time taken
Substituting the value in the above formula, we get
x = 70/Time taken
Time taken = 70/x
Total time taken = 1 + 70/x hours
We already know from the above equations the total time taken for the entire trip is 2 hours.
∴ 1 + 70/x = 2
70/x = 2 - 1
70/x = 1
x = 70 km h¯¹
Thus, The bus should travel the next 70 km distance at a speed of 70 km h¯¹.
Answer:
The bus should travel the next 70 km distance at a speed of 70 km h¯¹.
Step-by-step explanation: