+89 Probability question
n is an integer chosen at random from the set
{5, 7, 9, 11 }
p is chosen at random from the set
{2, 6, 10, 14, 18}
What is the probability that n + p = 23 ?
+23252 You can get a sum of 23 by selecting a 5 from the first set and an 18 from the second set
or selecting a 9 from the first set and a 14 from the second set.
The probability of selecting a 5 from the first set is 1/4 and the probability of selecting an 18 from the second set is 1/5, so the probability of selecting a 5 from the first set and an 18 from the second set is 1/4 x 1/5 or 1/20.
The probability of selecting a 9 from the first set is 1/4 and the probability of selecting a 14 from the second set is 1/5, so the probability of selecting a 9 from the first set and a 14 from the second set is 1/4 x 1/5 or 1/20.
The probability of doing either of these two is found by adding the individual probabilities together: 1/20 + 1/20 = 1/10.
The answer is 1/10.
+89 This is strange. I did not ask this question I clicked to view and answer, it then went from guest to the user name of mine.
The question I did ask was this
http://web2.0calc.com/questions/prove-there-is-never-a-perfect-square-for-n-when-n-gt-2
that question then posted as written by a guest user though the name of mine was on it in the beginning.
Very strange things in this forum happens sometimes.
Geno, your answer to this question is well much better than the one I might post.
