Probability and Statistics - Online Test
Q1. The probability that a teacher will give an unannounced test during any class is. If a student is absent twice, then the probability that he misses atleast one test is
Answer : Option B
Explaination / Solution:
No Explaination.
Q2. In a group of students, mean weight of boys is 80 kg and mean weight of girls is 50kg.If the mean weight of all the students taken together is 60kg, then the ratio of the number of boys to that of the girls is
Answer : Option A
Explaination / Solution:
let the no. of boys be x and no. of girls be y
sum of weights of boys= 80x
sum of weights of girls = 50y
sum of weights of boys and girls together = 60(x + y)
hence, 80x + 50 y = 60x + 60y
which gives, 20x = 10 y
so, x:y = 1:2
Q3. If the probability for A to fail in an examination is 0.2 and that for B is 0.3, then the probability that either A fails or B fails is
Answer : Option A
Explaination / Solution:
No Explaination.
Q4. For a normal distribution, we have
Answer : Option D
Explaination / Solution:
As in normal distribution, the curve is symmetric and unimodal. So, mean is at peak, mode is also at peak and median as well.
Q5. In a single throw of two dice, the probability of getting a total of 7 or 9 is
Answer : Option D
Explaination / Solution:
No Explaination.
Q6. A box contains 100 tickets numbered 1, 2, 3, ….100. Two tickets are chosen at random. If it is given that the maximum number on the two chosen tickets is not more than 10, then the probability that the minimum number on them is not less than 5 is
Answer : Option B
Explaination / Solution:
No Explaination.
Q7. Let A and B be two independent events. The probability that both A and B occur is and the probability that neither A nor B occurs is . The respective probabilities of A and B are
Answer : Option B
Explaination / Solution:
No Explaination.
Q8. Two events A and B have probabilities 0.25 and 0.50 respectively. The probability that both A and B occur simultaneously is 0.14. Then the probability that neither A nor B occurs is
Answer : Option A
Explaination / Solution:
No Explaination.
Q9. India plays two matches each with West Indies and Australia. In any match the probabilities of India getting points 0, 1 and 2 are 0.45, 0.5 and 0.5 respectively. Assuming that the outcomes are independent, the probability of India getting atleast 7 points is
Answer : Option C
Explaination / Solution:
No Explaination.
Q10. An unbiased dice is rolled four times. The probability that the minimum number on any toss is not less than 3 is
Answer : Option B
Explaination / Solution:
No Explaination.
