Mr. Matthei bought a box of doughnuts on Monday and again on Wednesday. The doughnuts look the same on the outside, but have different fillings inside. Each box always contains the same number of each kind: 3 lemon and 6 chocolate. What's the likelihood that the first doughnut Mr. Matthei ate on both Monday and Wednesday had lemon filling inside?
please explain!
2007-04-13 18:28:57 · 6 answers · asked by Ha!! 2 in Science & Mathematics ➔ Mathematics
1 out of 3 chance on each day (3 lemons out of a total of 9 doughnuts). It does not matter what he picked on Monday, he will have the same probability of picking a lemon on Wednesday. And as Philo says below, 1/9 picking lemon on both days.
2007-04-13 18:31:58 · answer #1 · answered by Memo Erdes 3 · 1⤊ 0⤋
probability of eating a lemon on Monday is 3/9 or 1/3.
probability of eating a lemon on Wednesday is 3/9 or 1/3
1/3 * 1/3 = 1/9
2007-04-14 01:37:33 · answer #2 · answered by 7 · 0⤊ 0⤋
the chance the he ate a lemon doughnut on any one day would be 3/9. to find the chance that he would eat the same one again on the second day, multipy the chances of the two days.
3/9 x 3/9 = 9/81.
this simplifies to 1/9 or 11.1%
2007-04-14 01:33:50 · answer #3 · answered by azncr0wn 2 · 1⤊ 0⤋
prob(lemon Monday) = 3/9 = 1/3
prob(lemon Wednesday) = 3/9 = 1/3
prob(lemon both days) = 1/3 • 1/3 = 1/9
2007-04-14 01:33:24 · answer #4 · answered by Philo 7 · 1⤊ 0⤋
the probability of lemon doughnuts is 3/9 and for chocolate ones is 6/9 so suppose he ate a lemon one on monday
3/9
and again a lemon one one wednesday
3/9
till now we've got : (3/9)*(3/9)=9/81
now suppose he ate a chocolate one on first and second day
(6/9)*(6/9)=36/81
and the total probability:
(9/81)+(36/81)=45/81=5/9
easy huh?
ask me if it wasn't clear
2007-04-14 01:40:01 · answer #5 · answered by na 1 · 0⤊ 0⤋
1/2 there are twice as many chocolate as lemon.
but, someone got to Mr. Matthei, because donuts come a dozen to a box
2007-04-14 01:39:33 · answer #6 · answered by Anonymous · 0⤊ 0⤋