Four runners compete in a 100 m race. The table shows the time it took for each
 runner to finish the race.
 Runner
 Kent
 Shaun
 Cal
 Faith
 Time (s)
 14
 17
 15
 13
 a. i. Who came last in the race?
 ii. Explain how you could tell.
 b. i. What is the formula for working out speed?
 ii. What is Cal's speed during the race?