What is the probability of what?
Guessing them all correctly?
Getting half of the correct?
Getting them all wrong?
PLEASE be specific with your questions if you want WikiAnswers to help.
For each question the student has a 50% chance of answering right. We can express this as a fraction of 1 (1 being 100%): 1/2, i.e. 0.5 There are 5 questions, so the answer will be: 0.5*0.5*0.5*0.5*0.5=0.5^5=0.03125 or 3.125%
This is abinomial distribution; number of trials (n) is 5, probability of success (p) is 1/4 or 0.25. With this information you can go to a Binomial Distribution Table and find the solution. Within the section of values for n=5 and p=.25, read from the section the probability of 4 which is 0.0146 (see related link for table).
5 out of 10
Since there are 73 Women, and 18 men, there are 91 people all together. The probability of the student being a man is 18 men out of the 91 total people. So, 18/91 or .1978.
The probability of getting at least 1 answer correct = 1 - Probability of getting all answers correct.So in your case it for be P(at least 1 answer correct) = 1 - 1/256where 256 is your sample space, |S| = 2^8.
2
It is 0.0033
Since there are only two options for the answer, on average the student will answer half of the answers correctly.
25
If there are four possible answers to a question, then a guessed answer would have a probability of 1 in 4. If there are six questions, then the mean number of correct answers would be six times 1 in 4, or 1.5
7/128, or about 5.5% The student has a 1/2 probability of getting each question correct. The probability that he passes is the probability that he gets 10 correct+probability that he gets 9 correct+probability that he gets 8 correct: P(passes)=P(10 right)+P(9 right)+P(8 right)=[(1/2)^10]+[(1/2)^10]*10+[(1/2)^10]*Combinations(10,2)=[(1/2)^10](1+10+45)=56/1024=7/128.
The probability that the student will pass is; P(pass) = P(10) + P(9) + P(8) = [10C10 + 10C9 + 10C8] / (.5)10 = 56/1024 ~ ~ 0.0547 ~ 5.47% where nCr = n!/[r!(n-r)!]
For each question the student has a 50% chance of answering right. We can express this as a fraction of 1 (1 being 100%): 1/2, i.e. 0.5 There are 5 questions, so the answer will be: 0.5*0.5*0.5*0.5*0.5=0.5^5=0.03125 or 3.125%
This is abinomial distribution; number of trials (n) is 5, probability of success (p) is 1/4 or 0.25. With this information you can go to a Binomial Distribution Table and find the solution. Within the section of values for n=5 and p=.25, read from the section the probability of 4 which is 0.0146 (see related link for table).
Assuming the questions are answered at random, the probability is 0.000009, approx.
5 out of 10
0.05 I think is the answer