Group B

Welcome to your Group B

1. People were asked about the time in a week they spend in doing social work in their community. They said 10,7,13,20 and 15 hours respectively. Find the mean time in a week devoted by them for social work.
2. The points scored by a kabaddi team in a series of matches are as follows : 17, 2, 7, 27, 15, 5, 14, 8, 10, 24, 48, 10, 8, 7, 18, 28. Find the median of the points scored by the team.
3. Find the mean of the marks obtained by 30 students of class X of a school.10,20,36, 92,95,40,50,56,60,70,92,88,80,70,72,70,36,40,36,40,92,40,50,50,56,60,70,60,60,
4. The heights(in cm) of 9 students of a class are as follows:
155,160,145,149,150,147,152,144,148 .Find the median of this data.
5. Find the mean of the first eight natural numbers.
6. Find the mean of the first ten odd numbers.
7. Find the mean of the first seven multiples of 5
8. Find the mean of all the factors of 20.
9. Find the mean of all prime numbers between 50 and 80.
10. The number of children in 10 families of a locality are 2, 4, 3, 4, 2, 0, 3, 5, 1, and 6. Find the mean number of children per family.
11. The following are the numbers of books issued in a school library during a week:
105, 216, 322, 167, 273, 405 and 346.
Find the average number of books issued per day.
12. If the mean of observations x,x+2,x+4, x+6 and x+8 is 11,find the value of x.
13. Find the median of:
2, 10, 9, 9, 5, 2, 3, 7, 11.
14. Find the median of: 15, 6, 16, 8, 22, 21, 9, 18, 25.
15. Find the median of: 20, 13, 18, 25, 6, 15, 21, 9, 16, 8, 22
16. The following observation have been arranged in ascending order. If the median of the data is 63,find the value of X.
29, 32, 48, 50, x, x+2, 72, 78, 84, 95
17. The blood group of 30 students of class VIII are recorded as follows:
A, B, O, O, AB, O,A,O,B,A,O,B,A,O,O,A,AB,O,A,A,O,O,AB,B,A,O,B,A,B,O.
Represent this data in the form of a frequency distribution table. which is the most common , and which is the rarest, blood group among these students?
18. Three coins were tossed 30 times simultaneously. Each time the number of heads occurring was noted down as follows:
Prepare a frequency distributed table for the data given above
19. If the mean of five observations x, X+2, x+6, x+8, is 13, find the value of x and hence mean of the last three observations.
20. The mean weight of 6 boys in a group is 48kg. the individual weights of five of them are 51kg, 45kg, 49kg, 46kg, and 44kg. find the weight of the sixth boy.
21. The mean of the marks scored by 50 students was found to be 39.Later on it was discovered that a score of 43 was misread as 23. Find the correct mean.
22. The means of 20 numbers is 43. If 6 is subtracted from each of the number , what will be the new means?
23. Compute the median from the following data:
marks                         0-7  7-14  14-21  21-28  28-35  35-42  42-49
number of students : 3      4          7         11        0          16        9
24. In a hospital, the ages of diabetic patients were recorded as follows. Find the median age.
Age(in years) :  0-15    15-30     30-45     45-60    60-75
No.of Patients:    5            20           40           50          25
25. If the mean of the following frequency distribution is 24, find the value of p.
class :         0-10   10-20   20-30   30-40   40-50
frequency:    3            4           p           3           2
26. Development of a country can generally be determined by its:
27. Different persons could have different as well as conflicting notions of a country’s development. A fair and just path for all should be achieved. Interpret the concept being discussed here.
28. Proportion of literate population in the 7 and above age group is called as:
29. For calculating Body Mass Index (BMI), weight of the person is divided by the:
30. What proportion of the country is over using their groundwater reserves?
31. Resources which will get exhausted after years of use are:
32. What will be the top priority in the developmental goal of a landless labourer?
33. HDI stands for ‘Human Development Index’ that focuses on Fill in the blanks with one of the following options:
34. What would be the most promising source of energy fifty years from now and why?
35. Pick out the cause (from below) that enhances environmental degradation:
36. Accounting furnishes data on
37. Gross profit is
38. Net profit is computed in the
39. What will be ratio of simple to compound interest on two same sums invested in SBI at rate of interest of 8% kept for 3 years?
Raju invested Rs. 77500 in ICICI bank. In two years how much compound interest will he get, if the first year rate of interest was 10% and second year had 2% more than first year?
What will be difference in population 3 years ago and 2 years ago of Devon village, whose current population is 100000 and which is increasing at a rate of 25% every year?
42. Raj has Rs. 1301 with him. He divided it amongst his sons Prakash and Prashant and asked them to invest it at 4% rate of interest compounded annually. It was seen that Prakash and Prashant got same amount after 17 and 19 years respectively. How much did Raj give to Prashant?
43. The probability of each event, when a coin is tossed for 1000 times with frequencies: Head:455 & Tail: 545 is:
44. The sum of all probabilities equal to:
45. The probability of each event lies between
46. Three coins were tossed 200 times. The number of times 2 heads came up is 72. Then the probability of 2 heads coming up is:
A batsman hits boundaries for 6 times out of 30 balls. Find the probability that he did not hit the boundaries.
48. If P(E) = 0.44, then P(not E) will be:
49. If P(E) = 0.38, then probability of event E, not occurring is:
50. The probability of drawing an ace card from a deck of cards is:

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