if there are 4 addressed envelopes and 4 letters. then ,the chance that all the letters are not mailed through proper envelopes is
Answers
Answered by
1
Step-by-step explanation:
let's see
no. of addresed envelope= 4
no. of non. addresed envelope is 4
do probability should be :- no.of addresed envelope/no.of non addresed envelope
= 4/4=1
hope it helps:-)
komal8719:
No it's a wrong answer correct answer is 23/24
Answered by
1
Step-by-step explanation:
Total no of possibilities of putting letter in envelopes are 4*3*2*1 = 24
Possibilities of having at least one correct envelope = 1 + 6 + 2*4 = 15
Possibilities of no correct envelope = 24 - 15 = 9
Probability of those 9 possibilities = 9/24 = 3/8
please explain how you find the possibilities of having mailed atleast one correct envelope, by the way correct answer is23/24
At least one means either one correct only, two correct only, three correct only or all four correct
All four correct possibilities are clearly only one
Only three correct is not possible since is three are correct then the fourth has to go in the remaining envelope making it four correct
You can select any two of the four letters and put them in their correct envelopes which can be done in 6 ways, the remaining two must be in the wrong envelope which is only done in one way, so 6*1 = 1
Now put any one in the correct envelope (4 ways to do that since 4 letters), the remaining three should be in wrong envelopes which can be done in 2 ways,so 4*2 = 8
Total is 1+0+6+8 = 15
Similar questions