Cpt quantitative aptitude

Can anyone explain to me following queriesQ no-1.if n numbers are drawn at random without replacement from the set (1,2,3,...m) ,then variance(x) would be...?Q no-2.8 life insurance policies in a sample of 100 taken out of 20,000 policies were found to be insured for less than Rs10,000.how many policies in the whole lot can be expected to be insured for less than Rs10,000 at 95 confidence level?Q no-3. a random sample of a group of people is taken and 100 were found to be in favor of liberalizing licensing regulations.If the proportion of people in the population found in favor of liberalization with 95 confidence lies between 0.683 and 0.817,then the number of people in the group is...?Q no-4.A life insurance company 1500 policies averaging Rs 2000 on the lives at age 30.from experience ,it is found that out of 100000 alive at age 30,99,000 survive at age 31.what is the lower value of the amount that the company will have to pay in insurance during the year...?Q no-5.If it is known that the 95 LCL and UCL to population mean are 48.04 and 51.96 respectively,what is the value of population standard deviation when the sample size is 100...,?answers 1.(m 1)(m-n)/12n 2.1058 and 2142 3.160 4.Rs 6000 5.10