 Ask Remember Me? Mandanas Posts: 2, Reputation: 1 New Member #1 Jan 21, 2006, 11:03 AM
Probability
A man owns two old cars, A and B, and has trouble starting them on cold mornings. The probability both will start is 0.1; the probability B starts and A does not is 0.1; the probability that neither starts is 0.4.
a) Find the probability that car A will start.
b) Find the probability that car A will start, given car B starts.
c) Find the probability that car B will start, given car A starts.

Please show detailed solution. Thanks! reinsuranc Posts: 92, Reputation: 6 Junior Member #2 Jan 21, 2006, 05:35 PM
Draw a rectangle, representing the sample space. The sum of all probabilities in the rectangle equals 1.

Within the rectangle, draw two circles A and B that have a portion of their area overlapping.

There are four distinct non-overlapping areas:

1. The area where A and B overlap, whose probability is .1

2. The remaining portion of B, which is B but not A, and whose probability is also .1

3. The portion of the rectangle outside the two circles, which is neither A nor B, and whose probability is .4

4. The remaining portion of A, which is A but not B, and whose probability is also is 1 - (.1 +.1 +.4) = .4

Using the diagram,

a) areas 1 + 4: .4 + .1 = .5
b) area 1 / (areas 1 + 2): .1/.2 = .5
c) area 1 / (areas 1 + 4): .1/.5 = .2

 Question Tools Search this Question Show Printable Version Email this Page Search this Question: Advanced Search

## Check out some similar questions!

Probability [ 3 Answers ]

Two numbers are selected from the integers 1 to 11 inclusive, repetition being allowed.Find the probability that, (a) Both are prime (b) Both are powers of 2 (c) One is a prime and the other is a power of 2

Probability [ 1 Answers ]

One Ivy League University has found that 40% of its students withdraw without completing the intro statistic course. Assume thst 15 students have registered for the course this semester, find the probability that a. three or fewer will withdraw b. exactly five will withdraw c. what is the means...

Probability [ 1 Answers ]

I have a problem: if z=x+y then f(z)=? (f(x,y):is given) please help me

Probability [ 1 Answers ]

2000 applicants aged 18-25. Drug users non-drug users Positive test results 297 34 Negative test results 3 1666 An applicant has positive test results? An applicant tests positive and uses drugs?...