1. A couple has three children. Assuming that the probability of having a boy or a girl for each child are equally likely events. The probability that the couple has no boys or no girls is

2. the following table represents sales of a particular brand of shirts at a store for the past month. It cross - classifies sales according to colour and size. There are four colours and three sizes.

	Red	Blue	Green	Yellow	Total
Small	40	84	68	38	230
Medium	156	254	126	148	684
Large	104	118	104	260	586
	300	456	298	446	1,500

The probability that the next shirt sold is a medium blue shirt is:

3. A die is tossed. Let the event A = {observe an even number} and the event B = {observing a number greater than or equal to the number five}. P (B|A) is equal to:

4.A discrete random variable X has the following probability distribution.

X	0	1	2	3
P(x)	3/10	4/10	2/10	p

The Value of p is: