8. Five mark exercise problems - II

1. Two unbiased dice are rolled once. Find the probability of getting (i) a doublet (equal numbers on both dice) (ii) the product as a prime number (iii) the sum as a prime number (iv) the sum as \(1\).

 

Answer:

 

(i) A doublet \(=\) $\frac{i}{i}$

 

(ii) The product as a prime number \(=\) $\frac{i}{i}$

 

(iii) The sum as a prime number \(=\) $\frac{i}{i}$

 

(iv) The sum as \(1 =\)

 

2. Three fair coins are tossed together. Find the probability of getting (i) all heads (ii) atleast one tail (iii) atmost one head (iv) atmost two tails.

 

Answer:

 

(i) All heads \(=\) $\frac{i}{i}$

 

(ii) Atleast one tail \(=\) $\frac{i}{i}$

 

(iii) Atmost one head \(=\) $\frac{i}{i}$

 

(iv) Atmost two tails \(=\) $\frac{i}{i}$

 

3. A bag contains \(5\) red balls, \(6\) white balls, \(7\) green balls, \(8\) black balls. One ball is drawn at random from the bag. Find the probability that the ball drawn is:

 

(i) White \(=\) $\frac{i}{i}$

 

(ii) Black or red \(=\) $\frac{i}{i}$

 

(iii) Not white \(=\) $\frac{i}{i}$

 

(iv) Neither white nor black \(=\) $\frac{i}{i}$