Numbers 1 through 8 are written on a piece of paper. A monkey is made to pick a number (one at a time) until it picks an even number. What is the probability that the monkey picks an 8 ???
2007-03-19 01:46:58 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
I'm not sure whether my method of approaching the problem is correct. But I'll describe it for your consideration.
1. The monkey picks one number at a time, at random and without replacement.
2. The monkey will continue to pick numbers until an even number is picked. It means that if #8 is picked, the monkey will stop picking.
Given the above conditions, under what circumstances will #8 be picked (#8 must be the last number picked because it's an even number)?
Case (a) 1st number is #8
Case (b) 1st number is Odd & 2nd number is #8
Case (c) 1st & 2nd numbers are Odd & 3rd number is #8
Case (d) 1st, 2nd & 3rd numbers are Odd & 4th number is #8
Case (e) 1st, 2nd, 3rd & 4th numbers are Odd & 5th number is #8
The final answer is 1/4.
2007-03-19 02:11:03 · answer #1 · answered by wysely 4 · 0⤊ 0⤋
the answer is not 1/4 because this neglects the cases where 8 is not picked at all. the monkey could pick all the odds and then 2 for example, and 8 would not be picked at all. adding these cases to the above, you would have:
case f) monkey picks 2
g) monkey picks 1 then 2
... and so on
2007-03-19 09:27:21 · answer #2 · answered by metalluka 3 · 0⤊ 0⤋
1 to 8.
2007-03-19 08:50:39 · answer #3 · answered by dgreer58 3 · 0⤊ 0⤋
1/4
2007-03-19 08:52:33 · answer #4 · answered by Anonymous · 0⤊ 0⤋
1/4
2007-03-19 08:51:42 · answer #5 · answered by gebobs 6 · 0⤊ 0⤋