Which quantity is bigger?
Tavi drives 113 miles at 50 miles per hour and return via the same route at 60 miles per hour.

Quantity A: Tavi's average speed for the entire round trip

Quantity B : 55mph

IApparently the answer is B , but I don't get why ? i thought I could calculate the average speed by by

(113*50+113*60) / (2*113)= 55 mph.....but it isn't right why?

Question

Which quantity is bigger? 
Tavi drives 113 miles at 50 miles per hour and return via the same route at 60 miles per hour.

Quantity A: Tavi's average speed for the entire round trip

Quantity B : 55mph

IApparently the answer is B , but I don't get why ? i thought I could calculate the average speed by by
 
(113*50+113*60) / (2*113)= 55 mph.....but it isn't right why?

calculusxy · Answer

Speed (s) is equaled to distance (d) over time (t).

calculusxy · Answer

What you have to do is break up the computations. Well the distance is 113 miles being driven.

calculusxy · Answer

And the time is both 60 and 50. So I think that you have to double 113 miles (since it is a round trip) and then divide the sum of 50 and 60.

calculusxy · Answer

A similar mathematical equation would be (113x2)/(50+60)

calculusxy · Answer

@arykk What do you think of this?