Yesterday you walked 20 meters to the right from your house to the bus stop, which took you 20 seconds. You waited at the bus stop for 1 minute before realizing you forgot your Mathematics homework at home. You ran back to your house in 5 seconds. It took you 10 seconds to find your homework, and then you ran back to the bus stop in 5 seconds just in time to catch the bus. What was your average velocity for the entire period of motion?



a.
0.2 m/s


b.
1 m/s

c.
100 m/s

d.
20 m/s