Question 1144384
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First part of the ride is 1.5*10 = 15 kilometers.


Second part of the ride is 0.5*13 = 6.5 kilometers.


The entire distance is  15 + 6.5 = 21.5 kilometers.


The total time is 1.5 + 0.5 = 2 hours.


The average rate (or speed) is   {{{total_distance/total_time}}} = {{{21.5/2}}} kilometers per hour.


This answer is correct, if the path is rectilinear.

Then the speed and the velocity are almost synonymous.


But if the path is curvilinear,  <U>then the given data IS NOT ENOUGH to answer the question</U>.
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You should know the difference between the rate (= the speed)  and velocity.


The first one is a number, while the second one is a vector.