# Thread: number of accidents probablitiy

1. ## number of accidents probablitiy

7 accidents occur in a week. What is the probablitiy that all the accidents occur in the same day??

THis is what aI did. I assumed , that the probablitiy of an accident occuring is equally likey, so the probablitiy of an accident occuring in a day is 1/7 .. the probablity of a second accident in a day is 1/7 also... so P ( 1st accident & 2nd & 3rd ..... 7th ) should be (1/7 )^7 right ?? but answer is ( 1/7 )^ 6

2. Originally Posted by ice_syncer
7 accidents occur in a week. What is the probablitiy that all the accidents occur in the same day??

THis is what aI did. I assumed , that the probablitiy of an accident occuring is equally likey, so the probablitiy of an accident occuring in a day is 1/7 .. the probablity of a second accident in a day is 1/7 also... so P ( 1st accident & 2nd & 3rd ..... 7th ) should be (1/7 )^7 right ?? but answer is ( 1/7 )^ 6
There are 7 days, each which could be the 'lucky' day. So you have to multiply your answer by 7.

3. OH OK you mean, P(sunday OR monday ..... SAT ) ? I see.