probability and odds?

Question

a) during a difficult realease move, a gymnast has fallen from the parrallel bars in 2 of 12 competitions this season. The state meet is next week. what is the probability that she will successfully complete the release move?

b) In 1995 there were 1227 hazardous waste sites, which 1074 were nonfederal sites. the newspaper carried a story about a hazardous waste site. what are the odds that it was a federal site?

Answer 1

a) 10/12 = 5/6 = 83.33%


b) the probability that the hazardous waste site was a federal site is 1227-1074=153/1227 = 12.5%

Answer 2

Probability is a fraction, part / whole
Odds is a ratio of two distinct outcomes,
such as
yes votes : no votes
true answers : false answers
wins : losses

(a) 10 successes out of 12 = 10/12 = 5/6
the answer that converted this to a percentage is correct
(b) 153 federal : 1074 nonfederal = 153:1074
since most were nonfederal, the odds are against it being a federal site

Answer 3

These are the dumbest word problems I've ever seen--they force you to make invalid, illogical inferences to come up with any answer. Here is the only answer you could use in a math class.

a) 1:6 16.7% (assuming the gymnast is having trouble with the release move, and will attempt it again at states, and is no better at performing it by then)
b) 87.5% (unless one type of site is better kept than the other--in that case, the worst kept would have the greater odds.)

Do you go to a school where you aren't allowed to talk about cards and dice? You need examples where probability is based on fewer unknown variables.