Average – Set 2

1) Find the average of cubes of first 49 positive integers?

2) The average weight of 15 students in a class increases by 1.5 kg when one of the students weighing 40 kg is replaced by a new student. What is the weight (in kg) of the new student ?

3) In a family of 5 members, the average age at present is 33 years. The youngest member is 9 years old. The average age of the family just before the birth of the youngest members was?

4) The average age of 30 boys in a class in 15 years. One boy, aged 20 years, left the class, but two new boys came in his place whose age differs by 5 years. If the average age of all the boys now in the class becomes 15 years, the age of the younger newcomer is ?

5) The average of a collection of 20 measurements was calculated to tb 56 cm. But later it was found that a mistake had occurred in one of the measurement which was recorded as 64 cm., but should have been 61 cm. The correct average must be ?

6) The mean high temperature of the first four days of a week is 25°C whereas the mean of the last four days is 25.5°C. If the mean of the whole week is 25.2°C then the temperature of the 4th day is ?

7) The average weight of five persons sitting in a boat is 38 kg. The average weight of the boat and the persons sitting in the boat is 52 kg. What is the weight of the boat ?

8) The mean of 50 numbers is 30. Later it was discovered that two entries were wrongly entered as 82 and 13 instead of 28 and 31. Find the correct mean?

10) The average of all the odd integers between 2 an 22 is ?

11) The average of the first 100 positive integers is ?

12) The average weight of 12 parcels is 1.8 kg. Addition of another new parcel reduces the average weight by 50 gm. What is the weight of the new parcel ?

13) The average of some natural numbers is 15. If 30 is added to the first number and 5 is subtracted from the last number the average becomes 17.5 then the number of natural numbers is ?

14) The batting average for 40 innings of a cricket player is 50 runs. His highest score exceeds his lowest score by 172 runs. If these two innings are excluded, the average of the remaining 38 innings is 48 runs. The highest score of the player is ?

15) The average of six numbers is 20. If one number is removed, the average becomes 15. What is the number removed ?

16) The average weight of a group of 20 boys was calculated to be 89.4 kg and it was later discovered that one weight was misread as 78 kg instead of 87 kg. The correct average weight is ?

17) The average age of a class of 39 students is 15 years. If the age of the teacher is included, then the average increases by 3 months. Find the age of the teacher?

18) The average of six numbers is 32. If each of first three numbers is increased by 2 and each of the remaining three numbers is decreased by 4, then the new average is ?

19) If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55 and 60, then the average marks of all the students is ?

20) The average marks obtained by 22 candidate in an examination are 45. The average marks of the first 10 candidates is 55 and those of the last eleven is 40. The number of marks obtained by the eleventh candidate is ?

22) Out of four numbers the average of the first three is 16 and that of the last three is 15. If the last number is 20, than first number is?

23) The average expenditure of a man for the first five months Rs. 1200 and for the next seven months is Rs. 1300. If he saves Rs. 2900 in that years, his monthly average income is ?

24) B was born when A was 4 years 7 months old and C was born when B was 3 years 4 months old. When C was 5 years 2 months old, then their average age was ?

25) Average weight of 25 persons is increased by 1 kg when one person weighing 60 kg is replaced by a new person. Weight of new the person is?

26) Out of 10 teachers of a school, one teacher retires and in place of him a new teacher 25 years old joins. As a result of it average age of the teachers reduces by 3 years. Age of the retired teacher (in years) is ?

27) The average of 50 numbers is 38. If two numbers, namely 45 and 55 are discarded, the average of the remaining numbers is ?

28) The arithmetic mean of the following numbers : 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6 and 7, 7, 7, 7, 7, 7, 7 is ?

29) Six tables and twelve chairs were bought for Rs. 7800. If the average price of a table is Rs. 750, then the average price of a chair would be ?

30) Eight consecutive numbers are given. If the average of the two numbers that appear in the middle is 6, then the sum of the eight given numbers is ?

31) The average age of mother and her six children is 12 years, which is reduced by 5 years if the age of mother is excluded. The age of the mother (in years) is ?

32) The mean of 9 observation is 16. One more observation is included and the new mean becomes 17. The 10^th observation is ?

33) The average temperature on Tuesday, Wednesday, and Thursday was 41 degrees, and on Wednesday, Thursday and Friday was 40 degrees. If on Friday it was exactly 39 degrees, then what was the temperature on Tuesday?

34) There are 50 students in a class. Their average weight is 45 kg. When one student leaves the class the average weight reduces by 100 g. What is the weight of the student who left the class ?

36) The average age of 11 players of a cricket team decreases by 2 months when two new players are included in the team replacing two players of age 17 years and 20 years. The average age of new players is ?

37) The average weight of first 11 persons among 12 persons is 95 kg. The weight of 12^th person is 33 kg more than the average weight of all the 12 persons. The weight of the 12^th person is ?

38) Mukesh has twice as much money as Soham. Soham has 50% more money than Pankaj. If the average money with them is Rs. 110, then Mukesh has ?

39) The average age of Ram and his two children is 17 years and the average age of Ram’s wife and the same children is 16 years. If the age of Ram is 33 years, the age of his wife is (in years) ?

40) Mean of 10 numbers is 30. Later on it was observed that numbers 15, 23 are wrongly taken as 51, 32. The correct mean is ?

42) A cricketer whose bowling average is 24.85 runs per wickets, takes 5 wickets for 52 runs in next inning and thereby decreases his average by 0.85. The number of wickets taken by him till the last match was ?

43) A batsman in his 12^th innings makes a score of 63 runs and there by increases his average score by 2. What is his average after the 12^th innings ?

44) In the afternoon, a student read 100 pages at the rate of 60 pages per hour. In the evening, when she was tired, she read 100 more pages at the rate of 40 pages per hour. What was her average rate of reading the pages per hours ?

45) A cricketer whose bowling average is 24.85 runs per wickets, takes 5 wickets for 52 runs in next inning and thereby decreases his average by 0.85. The number of wickets taken by him till the last match was ?

46) Average of first five odd multiples of 3 is ?

47) There are two groups A and B of a class, consisting of 42 and 28 students respectively. If the average weight of group A is 25 kg and that of group B is 40 kg, find the average weight of the whole class?

49) A cricketer has a mean score of 60 runs in 10 innings. Find out how many runs are to be scored in the eleventh innings to raise the mean score to 62 ?