1. If a person can select three presents from ten presents under a Palm tree, how many different combinations are there?

2. In a health center department, there are 8 nurses and 5 physicians; 7 nurses and 3 physicians are females. In a staff person is selected, find the probability that the subject is nurse or male.

a. Staff | females / males / total.

b. Nurse | 7 / 1 / 8.

c. Physicians | 3 / 2 / 5.

10 / 3 / 13.

3. A bag contains 5 balls. Two are numbered 3, one is numbered 4 and two are numbered 5. Balls are mixed and one is selected at random. After a ball is selected, its number is recorded. Then it is replaced. If the experiment is repeated many times, find mean, variance and standard deviation of number on ball.

4. Number of calls coming to customer care of a telecommunication company per minute is a Poisson random variable with mean 5. Find the probability that no calls are in certain minute.

5. The frequency distribution shows the salaries in million for specific year of top 25ceos in the United Kingdom. Find the mean, variance and standard deviation.

Class Boundaries | Frequency

15.5-20.5 | 13

20.5-25.5 | 6

25.5-30.5 | 4

30.5-35.5 | 1

35.5-40.5 | 1.

6. The number of traffic violation recorded by the traffic police office for 10-day period is given. Calculate the first quartile, second quartile, third quartile and inter quartile range.

22 | 19 | 25 | 24 | 18 | 15 | 9 | 12 | 16 | 20.