Mark S. answered 03/22/15
Tutor
New to Wyzant
Math, Science, Standardized Tests
1. To get the percentage of water bottles used per contestant, you divide the number of water bottles used by the number of contestants. Ergo,
41/96 = 0.427 = 42.7%
84/215 = 0.391 = 39.1%
107/255 = 0.420 = 42.0%
2. The key here is to recognize that the number of water bottles provides is not a relevant number, since it's always less than the number needed. We assume that water bottle usage is the average of the last three races, which gives
(0.427 + 0.391 + 0.420)/3 = 0.413 = 41.3%
Since there are 150 contestants, we figure
(150 contestants) * (0.413 bottles per contestant) = 62 bottles