In a triathlon, athletes swim , bicycle and then run .

Their total time includes transition time from one activity to the next.

Find the graph best represents a participant in a triathlon :

Observe the graphs :

Graph  represents an athlete going the same speed the entire race, Graph  had three different speeds and two stopping points and Graph  has two different speeds and one sopping period.

Since, there must be two stopping periods in a triathlon, graph is the best represents a participant in a triathlon.

The Graph is the best represents a participant in a triathlon.