## What is Average Formula?

An average is a term we used to hear in the statistics and mathematician the statistics average called Mean. Average play a very important role in the statistics if anyone wants to know the central value from available data they can use function average. In excel also we can easily find out average or mean according to our needs. An average is a statistics term, in a simple term we can say an average is a single number taken as representative of the list available. An average is used by many researchers at the time of doing research, But mainly average used by technical analyst because they have to calculate the average price of particular stock in which they are doing research, so they average having more importance in their field. An average is a middle number in the data.

The formula for Average –

**Average = Total Sum of All Numbers / Number of Item in the Set**

1. The average of marks of 14

student was calculated as 71.

But it was later found that the

marks of one student had been

wrongly entered as 42 instead of

56 and of another as 74 instead

of 32. The correct average is :

(1) 67 (2) 68

(3) 69 (4) 71

(SSC CGL Prelim Exam. 27.02.2000

(Second Sitting)

2. The average weight of three men

A, B and C is 84 kg. D joins them

and the average weight of the four

becomes 80 kg. If E whose weight

is 3 kg more than that of D,

replaces A, the average weight of

B, C, D and E becomes 79 kg.

The weight of A is

(1) 65 kg. (2) 70 kg.

(3) 75 kg. (4) 80 kg.

(SSC CGL Prelim Exam. 11.05.2003

(Second Sitting)

3. The average of a collection of 20

measurements was calculated to

be 56 cm. But later it was found

that a mistake had occurred in

one of the measurements which

was recorded as 64 cm., but

should have been 61 cm. The

correct average must be

(1) 53 cm (2) 54.5 cm

(3) 55.85 cm (4) 56.15 cm

(SSC CPO S.I. Exam. 07.09.2003)

4. The average of marks in Mathematics for 5 students was found

to be 50. Later, it was discovered

that in the case of one student

the marks 48 were misread as

84. The correct average is :

(1) 40.2 (2) 40.8

(3) 42.8 (4) 48.2

(SSC CPO S.I. Exam. 26.05.2005)

5. The average weight of 15 students

in a class increases by 1.5kg

when one of the students weighing 40 kg is replaced by a new

student. What is the weight (in

kg) of the new student ?

(1) 64.5 kg. (2) 56 kg.

(3) 60 kg. (4) 62.5 kg.

(SSC CPO S.I. Exam. 06.09.2009)

6. The average marks of 100 students were found to be 40. Later

on it was discovered that a score

of 53 was misread as 83. Find

the correct average corresponding to the correct score.

(1) 38.7 (2) 39

(3) 39.7 (4) 41

(SSC CPO S.I. Exam. 06.09.2009)

7. 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 87kg. The correct

average weight is

(1) 88.95 kg (2) 89.25 kg

(3) 89.55 kg (4) 89.85 kg

(SSC CGL Tier-1 Exam 19.06.2011

(First Sitting)

8. The average of 18 observations

is recorded as 124. Later it was

found that two observations with

values 64 and 28 were entered

wrongly as 46 and 82. Find the

correct average of the 18 observations.

(1) 111 7

9

(2) 122

(3) 123 (4) 137 3

9

(SSC CGL Tier-1 Exam 19.06.2011

(Second Sitting)

9. 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.

(1) 36.12 (2) 30.66

(3) 29.28 (4) 38.21

(SSC CGL Tier-1 Exam 26.06.2011

(First Sitting)

10. The average of 25 observations

is 13. It was later found that an

observation 73 was wrongly entered as 48. The new average is

(1) 12.6 (2) 14

(3) 15 (4) 13.8

(SSC CGL Tier-1 Exam 26.06.2011

(Second Sitting)

11. 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

(1) 25.5 (2) 32

(3) 30 (4) 34·5

(SSC CPO (SI, ASI & Intelligence Officer)

Exam 28.08.2011 (Paper-I)

12. The mean of 50 observations was

36. It was found later that an

observation 48 was wrongly taken

as 23. The corrected (new) mean is

(1) 35.2 (2) 36.1

(3) 36.5 (4) 39.1

(SSC CGL Prelim Exam.11.05.2003

(Second Sitting)

13. While finding the average of 10

given numbers, a student, by

mistake, wrote 64 in place of a

number 46 and got his correct

average 50. The correct average

of the given numbers is :

(1) 48.2 (2) 48.3

(3) 49.1 (4) 49.3

(SSC CHSL DEO & LDC

Exam. 27.11.2010)

14. The average of 10 numbers is

calculated as 15. It is discovered

later on that while calculating the

average one number, namely 36,

was wrongly read as 26. The correct average is

(1) 20 (2) 18

(3) 16 (4) 14

(SSC CHSL DEO & LDC

Exam. 28.11.2010 (Ist Sitting)

15. A student finds the average of ten

2-digit numbers. While copying

numbers, by mistake, he writes

one number with its digits interchanged. As a result his answer

is 1.8 less than the correct answer. The difference of the digits

of the number, in which he made

mistake, is

(1) 2 (2) 3

(3) 4 (4) 6

(SSC CHSL DEO & LDC

Exam. 28.11.2010 (IInd Sitting)

16. The average of 27 numbers is 60.

If one number is changed from

28 to 82, the average is

(1) 56 (2) 58

(3) 62 (4) 64

(SSC CISF Constable (GD)

Exam. 05.06.2011)

17. A tabulator while calculating the

average marks of 100 students

of an examination, by mistake

enters 68, instead of 86 and obtained the average as 58; the actual average marks of those students is

(1) 58.18 (2) 57.82

(3) 58.81 (4) 57.28

(SSC CHSL DEO & LDC

Exam. 04.12.2011 (Ist Sitting

(East Zone)

18. The mean of 20 items is 47. Later it is found that the item 62 is

wrongly written as 26. Find the

correct mean.

(1) 48·8 (2) 47·7

(3) 49·9 (4) 46·6

(SSC CHSL DEO & LDC

Exam. 04.12.2011 (IInd Sitting

(East Zone)

19. The mean value of 20 observations was found to be 75, but later

on it was detected that 97 was

misread as 79. Find the correct

mean.

(1) 75.7 (2) 75.8

(3) 75.9 (4) 75.6

(SSC CHSL DEO & LDC

Exam. 11.12.2011 (IInd Sitting

(East Zone)

20. The mean of 100 items was 46.

Later on it was discovered that

an item 16 was misread as 61

and another item 43 was misread as 34. It was also found that

the number of items were 90 and

not 100. Then what is the correct mean ?

(1) 50 (2) 50.7

(3) 52 (4) 52.7

(SSC Graduate Level Tier-II

Exam.16.09.2012)

21. The average of seven numbers is

18. If one of the number is 17

and if it is replaced by 31, then

the average becomes :

(1) 21.5 (2) 19.5

(3) 20 (4) 21

(SSC CHSL DEO & LDC

Exam. 21.10.2012 (IInd Sitting)

22. In an exam, the average marks

obtained by the students was

found to be 60. After omission of

computational errors, the average marks of 100 candidates had

to be changed from 60 to 30 and

the average with respect to all the

examinees came down to 45

marks. The total number of candidates who took the exam, was

(1) 200 (2) 210

(3) 240 (4) 180

(SSC Assistant Grade-III

Exam. 11.11.2012 (IInd Sitting)

23. In an examination, the average

of marks was found to be 50.

For deducting marks for computational errors, the marks of

100 candidates had to be

changed from 90 to 60 each and

so the average of marks came

down to 45. The total number

of candidates, who appeared at

the examination, was

(1) 600 (2) 300

(3) 200 (4) 150

(SSC CPO S.I. Exam. 12.12.2010

(Paper-I)

24. The average of l0 items was found

to be 80 but while calculating, one

of the items was counted as 60

instead of 50. Then the correct

average would have been :

(1) 69 (2) 79.25

(3) 79 (4) 79.5

(SSC Multi-Tasking Staff

Exam. 10.03.2013)

25. The average of 9 integers is found

to be 11. But after the calculation, it was detected that, by mistake, the integer 23 was copied

as 32, while calculating the average. After the due correction is

made, the new average will be

(1) 10 (2) 9

(3) 10.1 (4) 9.5

(SSC Constable (GD)

Exam. 12.05.2013)

26. The average weight of 20 students

in a class is increased by 0.75 kg

when one of the students weighing

30 kg is replaced by a new

student. Weight of the new

student (in kg) is :

(1) 35 (2) 40

(3) 45 (4) 50

(SSC CGL Prelim Exam. 27.02.2000

(Second Sitting)

27. Average weight of 25 persons is

increased by 1 kg when one

man weighing 60 kg is replaced

by a new person. Weight of new

person is :

(1) 50 kg (2) 61 kg

(3) 86 kg (4) 85 kg

(SSC CGL Prelim Exam. 08.02.2004

(Second Sitting)

28. There are 50 students in a class.

One of them weighing 50 kg goes

away and a new student joins.

By this the average weight of the

class increases by

1/2

kg. The

weight of the new student is :

(1) 70 kg (2) 72 kg

(3) 75 kg (4) 76 kg

(SSC CGL Prelim Exam. 08.02.2004

(Second Sitting)

29. The average weight of the 8 oarsmen in boat is increased by 1

1/2kg when one of the crew who

weighs 60kg is replaced by a new

man. The weight of the new man

(in kg) is

(1) 70 kg (2) 68 kg

(3) 71 kg (4) 72 kg

(SSC CHSL DEO & LDC Exam.

28.10.2012, Ist Sitting)

30. The average weight of 12 crewmen in a boat is increased by

1/3

kg, when one of the crewmen

whose weight is 55kg is replaced

by a new man. What is the weight

of that new man?

(1) 58 kg (2) 60 kg

(3) 57 kg (4) 59 kg

(SSC CHSL DEO & LDC

Exam. 04.11.2012, Ist Sitting)

31. The average marks obtained by

22 candidates in an examination

are 45. The average marks of the

first 10 candidates are 55 and

those of the last eleven are 40.

The number of marks obtained

by the eleventh candidate is

(1) 45 (2) 0

(3) 50 (4) 47.5

(SSC CGL Tier-I Re-Exam. (2013)

20.07.2014 (Ist Sitting)

32. The mean of 20 items is 55. If

two items 45 and 30 are removed, the new mean of the remaining items is

(1) 65.1 (2) 65.3

(3) 56.9 (4) 56

(SSC CGL Tier-I Re-Exam. (2013)

20.07.2014 (IInd Sitting)

33. The average marks obtained by

40 students of a class is 86. If

the 5 highest marks are removed,

the average reduces by one

mark. The average marks of the

top 5 students is

(1) 92 (2) 96

(3) 93 (4) 97

(SSC CGL Tier-I Exam. 19.10.2014)

34. The average of 50 numbers is

38. If two numbers, namely 45

and 55 are discarded, the average of the remaining numbers is

(1) 37.5 (2) 37.9

(3) 36.5 (4) 37.0

(SSC CGL Tier-I Exam. 26.10.2014)

35. The average of six numbers is

20. If one number is removed,

the average becomes 15. What

is the number removed ?

(1) 5 (2) 35

(3) 112 (4) 45

(SSC CGL Tier-II Exam. 21.09.2014)

36. The average marks secured by

36 students was 52. But it was

discovered that an item 64 was

misread as 46. What is the correct mean of marks ?

(1) 54 (2) 53.5

(3) 53 (4) 52.5

(SSC CHSL DEO & LDC

Exam. 16.11.2014)

37. A boy found that the average of

20 numbers is 35 when he

writes a number ‘61’ instead of

‘16’. The correct average of 20

numbers is

(1) 32.75 (2) 37.25

(3) 34.75 (4) 34.25

(SSC CAPFs SI, CISF ASI & Delhi

Police SI Exam. 22.06.2014

TF No. 999 KP0)

38. The average of 20 numbers is

calculated as 35. It is dicovered

later, that while calculating the

average, one number, namely

85, was read as 45. The correct

average is

(1) 36.5 (2) 37

(3) 37.5 (4) 36

(SSC CGL Tier-II Exam, 2014 12.04.2015

(Kolkata Region)

TF No. 789 TH 7)

39. The average marks obtained by

a student in 6 subjects is 88.

On subsequent verification it was

found that the marks obtained

by him in a subject was wrongly

copied as 86 instead of 68. The

correct average of the marks obtained by him is

(1) 87 (2) 85

(3) 84 (4) 86

(SSC CGL Tier-I Exam, 16.08.2015

(Ist Sitting) TF No. 3196279)

40. The average of 100 items was

found to be 30. If at the time of

calculation, two items were

wrongly taken as 32 and 12 instead of 23 and 11, then the correct average is :

(1) 29.8 (2) 29

(3) 29.9 (4) 29.5

(SSC CGL Tier-I (CBE)

Exam. 06.09.2016 (IInd Sitting)

ANSWER:

1. (3) 2. (3) 3. (3) 4. (3)

5. (4) 6. (3) 7. (4) 8. (2)

9. (3) 10. (2) 11. (1) 12. (3)

13. (1) 14. (3) 15. (1) 16. (3)

17. (1) 18. (1) 19. (3) 20. (2)

21. (3) 22. (1) 23. (1) 24. (3)

25. (1) 26. (3) 27. (4) 28. (3)

29. (4) 30. (4) 31. (2) 32. (3)

33. (3) 34. (1) 35. (4) 36. (4)

37. (1) 38. (2) 39. (2) 40. (3)