The probability is (1/2)25 = 1/33554432 = 0.00000003, approx
The probability of correct true & false question is 1/2 and the probability correct multiple choice (four answer) question is 1/4. We want the probability of correct, correct, and correct. Therefore the probability all 3 questions correct is 1/2 * 1/2 * 1/4 = 1/16.
If you answer randomly, 1 in 8.
It is 0.0547
5 out of 10
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.
50%
The probability of getting a perfect score in a three-question true or false quiz is 100% if you studied and retained the subject matter and the questions addressed that subject. If, however, you did not study, and you made pure guesses without any bias towards an answer partially based in your (now rather poor) knowledge, then the probability of getting any one question correct is 50%, so the probability of getting all three questions correct is 50% to the third power, or 12.5%.
The probability of correct true & false question is 1/2 and the probability correct multiple choice (four answer) question is 1/4. We want the probability of correct, correct, and correct. Therefore the probability all 3 questions correct is 1/2 * 1/2 * 1/4 = 1/16.
If you answer randomly, 1 in 8.
It is 0.0547
The probability of getting the first answer correct is 1/2 The probability of getting the first two correct is 1/2 * 1/2 = 1/(22) The probability of getting all 9 correct is 1/(29) = 1/512 which is just under 0.2%
50%
5 out of 10
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.
Probability, P, of 70% or more correct (7 or more correct) is: P(7) + P(8) + P(9) + P(10). See the related link; N=10, P = 0.5, and K = 7, 8, 9, & 10. Therefore the probability is: .11719 + .04395 + .00977 + .00098 = .17189 or approximately 17.2% probability 7 or more correct.
.00000003
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.