Question

Two dice are rolled one after the other. The probability that the number on the first is smaller than the number on the second is:

Solution

Correct option is

5/12

Two throws independent

So P(no. on D1 < no. on D2) = P(no. on D2 < no. on D1)

⇒    Let E1 = Number on D1 < D2     

              E2 = Number on D2 < D1

                F = Number on D2 < D1       

⇒    Let (E1) + P(E2) + P(F) = 1

⇒    2P(E1) + P(F) = 1…….(i)

P(F) = P(1) P(1) + P(2) P(2) +….+ P(6) P(6)

                    

SIMILAR QUESTIONS

Q1

If A1, A2,….An are any n events, then

Q2

The probability that at least one of the event A and B occurs is 0.6 if A and B occur simultaneously with probability 0.2, then 

Q3

Odds in favour of an event A is 2 to 1 and odds in favour of A∪ B are 3 to 1. Consistent with information the smallest and largest values for the probability of event B are given by:

Q4

An integer is chosen at random from the first 200 positive integers. The probability that the integer chosen is divisible by 6 or 8 is:

Q5

If ten objects are distributed at random among ten persons, the probability that at least one of them will not get object is:

Q6

If two events A and B are such that 

                       

Q7

One ticket is selected at random from 100 tickets numbered 00, 01, 02,…99. Suppose A and B are the sum and product of the digits found on the ticket. Then P(A = 7/8 = 0) is given by:

Q8

A box contain 100 tickets numbered 1, 2,…100. Two tickets are chosen at random. It is given that the greater number on the two chosen tickets is not more than 10. The probability that the smaller number is 5 is:

Q9

A bag contains four tickets marked with numbers 112, 121, 211, 222. One ticket is drawn at random from the bag. Let

Ei(i = 1, 2, 3) denote the event that its digit on the ticket is 2. Than:

Q10

There are 20 cards. 10 of these cards have the letter ‘I’ printed on them and the other 10 have the letter ‘T’ printed on them. If three cards are drawn without replacement and kept in the same order, the probability of making word IIT is: