This Paper has 62 answerable questions with 2 answered.
1—12(QNM) Revised Syllabus |
Time Allowed : 3 Hours | Full Marks : 100 |
The figures in the margin on the right side indicate full marks. |
(Notations and symbols used have their usual meanings) |
SECTION I (Mathematical Techniques — 40 marks) |
Answer Question No. 1 (Compulsory — 10 marks) and two other questions (15x2=30 marks) from this section. |
Marks |
1. | Attempt any five questions: Choose the correct options showing the proper reasons/calculations. | 2 x 5 | |
| (a) | (A) | | (B) | | (C) | | (D) | none of these | | | (1) |
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(b) | (A) | 18 | (B) | 324 | (C) | 0 | (D) | none of these | | | (0) |
| (c) | If p = 2i − j + k and q = i + j + k, then the magnitude of p x q is (A) | 14 | (B) | √14 | (C) | √41 | (D) | none of these | | | (0) |
| (d) | If f(x−1) = x2 − 4x+3 then f(x+1) is (A) | x2 | (B) | x2 – 1 | (C) | x2 + 1 | (D) | none of these | | | (0) |
| (e) | (A) | 1 | (B) | | (C) | 4 | (D) | none of these | | | (0) |
| (f) | If y = (a √x + b) (b √x + a) then the value of | | for a = b = 1 is |
(A) | | (B) | | (C) | | (D) | none of these | | | (0) |
| (g) | (A) | | (B) | log(e+1) | (C) | 1 | (D) | none of these | | | (0) |
| (h) | If the cost function c(x) = | | x3 – 3x2 + 25x + 5 | then at what output level, marginal cost is minimum? |
(A) | 1 | (B) | 2 | (C) | 3 | (D) | none of these | | | (0) |
| (i) | The extreme values of the function f(x) = x3 – 6x2+9x – 8 are at (A) | (1,2) | (B) | (1,3) | (C) | (–1, –3) | (D) | none of these | | | (0) |
| (j) | If f(x) = x3 + 2xy + y3 then the values of fxy and fyx are (A) | (2,2) | (B) | (3,3) | (C) | (2, 3) | (D) | none of these | | | (0) |
2. | (a) | If a = 2i + 5j + 3k, b = 3i + 3j + 6k, c = 2i + 7j + 4k, find (i) (a – b) x (c – a), (ii) | (a – b) x (c – a). | 5 | (0) |
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(b) | If A = | | , then find A2 and show that A2 = A–1. | | 5 | (0) |
| (c) | Solve by Cramer's rule showing the condition of consistency of solution: x+y+z = 6, x+2y+z =8, x+y+2z = 9 | 5 | (0) |
3. | (a) | For what value of a, f(x) = x +1 when x ≤ 1 3a – x when > 1 is continuous at x = 1? Hence determine f(2) − f(0) | 5 | (0) |
| (b) | if y = x + √1 – x2 prove that (y1 – 1)√1 – x2 + x = 0 and y2 (1 – x2) – xy1 + y = 0 where y1 = | 5 | (0) |
| (c) | The production function of a commodity is given by q = 20x+2x2 – | | where q is the total output for x | units of input. Verify that when average product is maximum, it is equal to marginal product. | 5 | (0) |
4. | (a) | Evaluate ∫ | 2x3 - 2x - 12 | 2x2 - 2x - 4 |
| dx for x ≠ 2. | | 5 | (0) |
| (b) | Using graph paper minimize the objective function z = 2x − y subject to the constraints x + y ≤ 5, x+2y ≤ 8, 4x+3y ≥ 12, x ≥ 0, y ≥ 0. | 5 | (0) |
| (c) | Is there any saddle point in the pay off matrix of the game between two players A and B? Determine the optimum strategies of the players and the value of the game. | 5 | (0) |
5. | (a) | In an Auto Hub, automobile cars arrive at a rate of 30 cars per day. Assuming that the inter-arrival time follows an exponential distribution and the service time distribution is also exponential with average 36 minutes, calculate the following. (i) | Mean queue size(line length); | (ii) | Probability that the queue size exceeds 10 | | 5 | (0) |
| (b) | Find the area bounded by the curves x2 = y and y2 = x by drawing the graphs | 5 | (0) |
| (c) | write short note on any one of the following | 5 | |
| | (i) | Slack and Surplus variable used in LPP | | (0) |
| | (ii) | Consumer’s Surplus and Producer’s Surplus | | (0) |
SECTION II (Statistical Techniques — 30 marks) |
Answer Question No. 6 (Compulsory — 10 marks) and any two other questions (10x2 = 20 marks) from this section. |
6. | Answer any five of the following. Choose the correct alternative stating proper reasons/calculations: | 2x5 | |
| (a) | For two independent events A and B, P(A) = | | , P(B) = |
| | then P (none of the events A and B occur) is |
(i) | | (ii) | | (iii) | | (iv) | none of these | | | (1) |
| (b) | If a random variable x follows Poisson distribution such that P(x = 1) = P(x = 0) = P(x = atmost 1) is (i) | 2e-1 | (ii) | e-1 | (iii) | | (iv) | none of these | | | (0) |
| (c) | If var (X) = var (Y) = | | and var (X + Y) = |
| | the correlation coefficient between random variables X and Y is |
(i) | | (ii) | | (iii) | | (iv) | none of these | | | (0) |
| (d) | 6 fair coins are tosses simultaneously. Probability of getting at least 4 heads is (i) | | (ii) | | (iii) | | (iv) | none of these | | | (0) |
| (e) | If x be a normal variate with mean 100 and variance 9 then the modal ordinate is (i) | | (ii) | | (iii) | | (iv) | none of these | | | (0) |
| (f) | If mean and variance of a binomial distribution are 4 and | | respectively, the values of n and p are |
(i) | | (ii) | | (iii) | | (iv) | none of these | | | (0) |
| (g) | The correlation coefficient of bivariate X and Y is 0.60. Variance of X is 2.25 and regression coefficient of Y on X is byx = 0.8. The value of s.d. of Y is (i) | 2 | (ii) | 4 | (iii) | 8 | (iv) | none of these | | | (0) |
| (h) | A lot of 100 items contains 20 defectives. If a sample random sample of size 10 is drawn without replacement (SRSWOR), the standard error(S.E.) of the sample proportion of defective items is (i) | | (ii) | | (iii) | | (iv) | none of these | | | (0) |
| (i) | If the samples of size n are drawn at random without replacement from the set {1, 2, 3, ......., N}, then var (x) is (i) | | (ii) | | (iii) | | (iv) | none of these | | | (0) |
| (j) | To test unbiasedness of a coin it is tossed 3 times and null hypothesis is accepted when number of heads obtained is atmost 2. Then probability of type I error is (i) | | (ii) | | (iii) | | (iv) | none of these | | | (0) |
7. | (a) | In a class of 10 students, any student can choose one of the two subjects X and Y. 6 students take X and the rest take Y. 3 students are selected at random (without replacement). Find the probability that (i) they all take X (ii) they all take Y (iii)at least one takes Y | 5 | (0) |
| (b) | A box contains 10 screws of which 5 are defectives. Obtain the probability distribution of the number of defective screws(x) in a sample of 4 screws chosen at random. Also find var (x). | 5 | (0) |
8. | (a) | In an office 40% of employees have scooters, 20% have cars and 80% of the employees who have scooters do not have cars. What is the probability that an employee has a car given that he does not have a scooter? | 5 | (0) |
| (b) | Find the Spearman's rank correlation coefficient from data of marks in Statistics and Economics of 9 students. Marks in Statistics: | 64 | 57 | 66 | 47 | 58 | 69 | 40 | 36 | 35 | Marks in Statistics: | 56 | 57 | 65 | 48 | 66 | 50 | 35 | 34 | 40 | | 5 | (0) |
9. | (a) | A company is trying to manufacture a new type of item. The relevant data are shown in the following table where first year profits in thousand rupees are given: Product line\State of nature | | Good | Fair | Poor | Probability: | 0.2 | 0.4 | 0.4 | Full | | 70 | 40 | -15 | Partial | | 60 | 45 | -10 | Minimal | | 40 | 30 | 0 |
(i) | Find the optimum product line and its expected profit | (ii) | Find the optimum value of expected opportunity hours and then optimum course of action | | 5 | (0) |
| (b) | A confectioner sells confectionery items. Past data of demand per week (in hundred kilograms) with frequency is given below: Demand | per week | : | 0 | 5 | 10 | 15 | 20 | 25 | 30 | Frequency | : | 2 | 9 | 6 | 18 | 9 | 4 | 2 | Using following sequence of random numbers generate the demand for next 15 weeks and also find the average demand per week. Random Numbers | 60 | 66 | 67 | 56 | 94 | 83 | 35 | 57 | 34 | 73 | 23 | 13 | 90 | 52 | 35 | 19 | | 5 | (0) |
10. | (a) | Find the means of two variables x and y and the correlation coefficient between x and y from two regression lines x+6y = 6 and 2x+3y = 9 | 5 | (0) |
| (b) | From a population of 5 members 10, 14, 14, 16, 18 draw all possible samples of size 2 with SRSWOR. Obtain the sampling distribution of sample mean and hence find its standard error. | 5 | (0) |
11. | (a) | Fit a Poisson distribution to the following data. Calculate the theoretical frequencies. [Given e-0.5 = 0.61] x | : | 0 | 1 | 2 | 3 | f | : | 121 | 61 | 15 | 3 | | 5 | (0) |
| (b) | Write short note on any one of the following: | 5 | |
| | (i) | Bayes theorem with one example; | | (0) |
| | (ii) | Properties of normal distribution. | | (0) |
SECTION II (Economic Techniques — 30 marks) |
12. | Answer any five of the following: | 2x5 | |
| (a) | If 15 | | % fall in price causes 6% rise in demand then demand is |
(i) | elastic | (ii) | inelastic | (iii) | none of these | | | (0) |
| (b) | If the demand function is p = 12-x2 then for what value of x is the elasticity of demand unity? (i) | 1 | (ii) | 2 | (iii) | 3 | (iv) | none of these | | | (0) |
| (c) | For the demand law p = | | ,the elasticity of demand in terms of x is | | | (0) |
| (d) | Given Ʃp0q0 = 200, Ʃp0q1 = 300, Ʃp1q0 = 250, Ʃp1q1 = 400 the Fisher's Ideal Index Number is (i) | 157 | (ii) | 167 | (iii) | 177 | (iv) | none of these | | | (0) |
| (e) | An index is at 100 in the year 2000. It rises 5% in 2001, falls 6% in 2002, further falls 7% in 2003 and then rises 10% next year. The net rise/fall w.r.to the base year is (i) | no rise | (ii) | no fall | (iii) | 1% rise | (iv) | 1% fall | | | (0) |
| (f) | If the cost C of output q is C = | | q3 - 5q2 then the marginal cost is minimum at output level |
(i) | 2 | (ii) | 3 | (iii) | 4 | (iv) | none of these | | | (0) |
| (g) | when r12 = 0.6, r23 = 0.8, r31 = 0.5, then value of R1.23 is (i) | 0.5 | (ii) | 0.6 | (iii) | 0.7 | (iv) | none of these | | | (0) |
| (h) | Taking 2000 as the base year, CLI in the year 2010 stands at 250. An employee drawing a monthly salary of Rs.800 in the year 2000, gets Rs. 1800 in 2010. How much is he getting more or less? (i) | Rs.200 more | (ii) | Rs.200 less | (iii) | Rs.400 more | (iv) | Rs.400 less | | | (0) |
| (i) | The second degree polynomial passing through the points (1, 3), (0, 4), and (-1, 9) is (i) | 2x2 -3x+4 | (ii) | 3x2 -2x+4 | (iii) | 4x2 -2x+3 | (iv) | none of these | | | (0) |
13. | Answer any four of the following: | 5x4 | |
| (a) | The demand curve for a commodity is given by p = 20 - √x where p and x are the price and amount of the commodity respectively. Find the marginal quantity demand and also average quantity demand. Find the elasticity of demand at a price p = 2 and state whether the demand is elastic or inelastic. | | (0) |
| (b) | The demand function for a particular brand of pocket radio is stated below: p = 100 - 0.4 Q - 0.006 Q2 Find the consumer's surplus at a quantity of 20 radios. | | (0) |
| (c) | Fit a straight line trend by the method of least squares from the following data: Year | : | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | Value | : | 15 | 18 | 16 | 18 | 20 | 19 |
and estimate the value for 2010. | | (0) |
| (d) | Given the following data: Commodity | Base year | Current Year | Price (p0) | Quantity (q0) | Price (p0) | Quantity (q0) | A B | 1 1 | 10 5 | 2 x | 5 2 | Find x, if the ratio between Laspeyre’s and Paasche’s index numbers is 28 : 27. | | (0) |
| (e) | If r12 = 0.5, r13 = 0.6, r23 = 0.7 determine r1.23 and r12.3. | | (0) |
| (f) | The coefficient matrix of input is | | and the vector of final demand is |
| | Find the gross production. | | (0) |
| (g) | write short note on any one of the following; | | |
| | (i) | Moving average method; | | (0) |
| | (ii) | Components of a time series; | | (0) |
| | (iii) | Multiple regression. | | (0) |