JEE MAINS QUIZ ON PROBABILITY

Consider the experiment of rolling a die. Let A be the event 'getting a prime number and B be the event 'getting an odd number. Then, which of the following is true?

1. A or B=A ∪ B = {1,2,3}
2. A and B=A ∩ B = {3,5}

III. A but not B = A – B = {2}

1. Not A = A’ = {1,5,6}

In a bag there are 21 balls marked by number 1,2,3, ..21. Two balls are drawn one by one with replacement. What is the probability that from drawn balls first shows odd number and second shows even number.

A bag contains 9 discs. Of which 4 are red, 3 are blue and 2 are yellow. The discs are similar in shape and size. A disc is drawn at random from the bag.

Let the events A, B and C be defined as

A: the disc drawn is red

B: the disc drawn is yellow.

C: the disc drawn is blue.

Then, which of the following is correct?

One die of red colour (R) one of white colour (W) and one of blue colour (B) are placed in a bag. One die is selected at random and rolled, its colour and the number on its uppermost face is noted. Then, the sample space is

From X = {1,2,...25}, a number is selected randomly from X and found to be prime. The probability that it is more than 12 is

Two aeroplanes I and II bomb a target in succession. The probabilities of I and II scoring a hit correctly are 0.3 and 0.2, respectively. The second plane will bomb only, if the first misses the target. The probability that the target is hit by the second plane, is