Help me out please and thank you!
1 answer:
You might be interested in
Answer:
A
Step-by-step explanation:
Given
a = -
=
← as a single fraction
Thus
=
=
→ A
A train needs 4 hours to go from the first station to the second and the total travel time must be no more than 7 hours, then the train needs at most 3 hours to go from the second station to the third station.
The average speed can be obtained by the formula:
Let V be the train speed between first and second stations, then the distance between the first and the second stations is 4V miles.
Therefore,
- the total distance is 4V+120 (V>0);
- the total time is T≤7 hours.
Now
The slowest average speed will be when nominator is the smallest and denominator is the greatest. The greatest denominator could be T=7, then