SOLUTION: The odds that a month, chosen at random, has 31 days is 7:5. Find the probability of that event. Write your answer as a fraction (n/d) in lowest terms. p(31)=

Algebra ->  Probability-and-statistics -> SOLUTION: The odds that a month, chosen at random, has 31 days is 7:5. Find the probability of that event. Write your answer as a fraction (n/d) in lowest terms. p(31)=      Log On


   

Question 1098320: The odds that a month, chosen at random, has 31 days is 7:5. Find the probability of that event. Write your answer as a fraction (n/d) in lowest terms. p(31)=
Answer by greenestamps(13203) About Me  (Show Source):
You can put this solution on YOUR website!

For the odds (n favor of) a particular outcome, the ratio is
(number of good outcomes) : {number of bad outcomes)

For probability, the ratio is
(number of good outcomes) / (total of all possible outcomes)

Note that it is customary to use the : when writing odds and the / when writing probabilities. You will sometimes see probabilities written with the : but that is confusing to many people.

There are 12 months, of which 7 have 31 days each and the other 5 do not. So while the odds of a month having 31 days is 7:5, the probability of a month having 31 days is 7/12.