Click off the first one because 180 (Thea) < 225 (Eleanor). Then keep the second one and click the third and fourth one.
10 km ÷ 2.5 hours = 4 km/h — This is Sara's record
7.5 km ÷ 2 hours = 3.75 km/h — This is Katerina's record
9.5 km ÷ 2.25 hours = 4.2 km/h — This is Candice's record
Therefore, the answer is Candice had the fastest average speed.
You can buy 5 bottles because $4 times 5 equals $20. I hope this helps :)
