The following is the time-distance graph of Sneha’s walking.
A) When does Sneha make the least progress? Explain your reasoning.
B) Find her average speed in km/hour.
A) From the graph we can say that , Sneha made the least progress from the interval 25 minutes to 40 minutes.
We see that initially , she is travelling approximately 0.5km in 10min , 0.25km in 5min , till the first 25 mins. But after 25 mins, her speed decreased as she travelled 0.25km in 15min.
We can say that because of her speed in that interval i.e. 
= 
= 1km/hr which the lowest among all.
B) As we know that ,
Average speed = 
= 
= 
= 
× 60 = 2.18km/hr.
∴ Average speed = 2.18km/hr.
65