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 –
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)
