A man walks half of his trip by 40km/hr and ride a bicycle the rest of his trip by 60km/hr. What is his average speed
total distance: 2d
total time: d/40 + d/60
avg speed: 2d/(d/40 + d/60) = 48 km/hr
Man, that guy is some fast walker and biker!
Note that this is really just one of those mixture problems in disguise.
2/s = 1/60 + 1/40
s = 48
It is spelled physic
actually, it's physics
a physic is a medicine or drug
To find the man's average speed, we need to first calculate the total distance traveled and then divide it by the total time taken.
Let's assume that the total distance of the trip is 'd' kilometers. Since the man walks half of the distance and rides the bicycle for the remaining half, we can say that he walks d/2 kilometers and rides the bicycle d/2 kilometers.
Now, let's calculate the time taken for each segment of the trip:
Time taken for walking = Distance / Speed = (d/2) / 40 km/hr = (d/2) * (1/40) hours
Time taken for riding the bicycle = Distance / Speed = (d/2) / 60 km/hr = (d/2) * (1/60) hours
The total time taken for the trip would be the sum of the time taken for walking and riding the bicycle:
Total Time = (d/2) * (1/40) + (d/2) * (1/60) hours
= d * [(1/2) * (1/40) + (1/2) * (1/60)]
Now, let's calculate the average speed:
Average Speed = Total Distance / Total Time
= (d + d) / [d * (1/2) * (1/40) + d * (1/2) * (1/60)]
= 2d / [d * (1/20) + d * (1/30)]
= 2 / [(1/20) + (1/30)]
= 2 / [(3/60) + (2/60)]
= 2 / (5/60)
= 2 * (60/5) km/hr
= 24 km/hr
Therefore, the man's average speed for the entire trip is 24 km/hr.