Thread: Probability help (this is driving me nuts) #3

I have been at this for 3 days already and i did some of them but i just am so confused that my brain hurts even trying to figure out if i am doing the right stuff. please please help me/ show me or point me in the right direction with these problems

1.English and American spellings are colour and color, respectively. A man staying at a
Parisian hotel writes this word, and a letter taken at random from his spelling is found to be a vowel. If
40 percent of the English-speaking men at the hotel are English and 60 percent are Americans, what is the
probability that the writer is an Englishman?


4. Three missiles are fired at a target and hit it independently with probabilities 0.6, 0.7, and
0.8, respectively. What is the probability that the target is hit?

Hello, SydneyBristow!

Here's the first one . . .

1. English and American spellings are "colour" and "color", respectively.
A man staying at a Parisian hotel writes this word, and a letter taken
at random from his spelling is found to be a vowel.
If 40% of the English-speaking men at the hotel are English and 60% are Americans,
what is the probability that the writer is an Englishman?

This requires repeated use of Bayes' Theorem . . .


We have: .

We want: .


From [1] we have: .

. .

From [2] we have: .

. .


Hence: .



Substitute [4] and [5] into [3]: .

. .

thankyou .

can you plz advise if for the missle problem my logic accurate?


1-(.4*.3*.2 )=.976


i cant type much as i hv newborn in my arns

Probability that at least 1 hits = 1-Probability that every one misses

=1-(.4*.3*.2) as you said, looks good to me