Compare the average speed in the following cases.

a. You walk 73.2 m at a speed of 1.2 m/s and then run 73.2 m at a speed of 3.1 m/s along a straight track
Subject: science

B. you walk for 1 minute at a speed of 1.2 m/s and then run for 1 minute at 3.1 m/s along a straight track

avg speed is totaldistance/totaltime.

So, since time = distance/speed,
and distance = speed * time, you need to compare
(73.2+73.2)/(73.2/1.2 + 73.2/3.1) vs (60*1.2 + 60*3.1)/(60+60)
or, simplifying the fractions a bit,
(1+1)/(1/1.2 + 1/3.1) vs (1.2+3.1)/(1+1)