1. The average of five numbers is 27.
If one number is excluded, the
average becomes 25. The
excluded number is :
(1) 25 (2) 27
(3) 30 (4) 35
(SSC CGL Prelim Exam. 04.07.1999 (Ist
Sitting) & (SSC SO (Commercial Audit)
Exam. 16.11.2003)
2. The average of marks of 28 students in Mathematics was 50; 8
students left the school, then this
average increased by 5. What is
the average of marks obtained by
the students who left the school ?
(1) 50.5 (2) 37.5
(3) 42.5 (4) 45
(SSC CGL Prelim Exam. 13.11.2005
(Second Sitting)
3. The average weight of 12 parcels
is 1.8 kg. Addition of another
new parcel reduces the average
weight by 50 g. What is the
weight of the new parcel ?
(1) 1.50 kg (2) 1.10 kg
(3) 1.15 kg (4) 1.01 kg
(SSC CPO S.I. Exam. 07.09.2003)
4. The average of 50 numbers is
38. If two numbers namely 45
and 55 are discarded, the average of the remaining numbers is :
(1) 35 (2) 32.5
(3) 37.5 (4) 36
(SSC Graduate Level Tier-I
Exam. 21.04.2013 (Ist Sitting)
5. There are 50 students in a class.
Their average weight is 45 kg.
When one student leaves the
class the average weight reduces by 100g. What is the weight
of the student who left the
class ?
(1) 45 kg (2) 47.9 kg
(3) 49.9 kg (4) 50.1 kg
(SSC CPO S.I.
Exam 12.12.2010 (Paper-I)
6. Average weight of 25 students
of a class is 50 kg. If the weight
of the class teacher is included,
the average is increased by 1 kg.
The weight of the teacher is
(1) 76 kg (2) 77 kg
(3) 74 kg (4) 75 kg
(SSC Multi-Tasking Staff
Exam. 17.03.2013, Ist Sitting)
7. There were 35 students in a hostel. If the number of students is
increased by 7 the expenditure on
food increases by 42 per day
while the average expenditure of
students is reduced by 1. What
was the initial expenditure on food
per day ?
(1) 400 (2) 432
(3) 442 (4) 420
(SSC Section Officer (Commercial
Audit) Exam. 25.09.2005)
8. The average of 6 observations is
45.5. If one new observation is
added to the previous observations, then the new average becomes 47. The new observation is
(1) 58 (2) 56
(3) 50 (4) 46
(SSC CGL Prelim Exam. 04.02.2007
(First Sitting)
9. The average of five numbers is
140. If one number is excluded,
the average of the remaining four
numbers is 130. The excluded
number is :
(1) 135 (2) 134
(3) 180 (4) 150
FCI Assistant Grade-III
Exam. 05.02.2012 (Paper-I)
East Zone (IInd Sitting)
10. The average of five numbers is
7. When three new numbers are
included, the average of the eight
numbers becomes 8.5. The average of the three new numbers is
(1) 9 (2) 10.5
(3) 11 (4) 11.5
(SSC CHSL DEO & LDC
Exam. 28.11.2010 (IInd Sitting)
11. The average of six numbers is 32.
If each of the first three numbers
is increased by 2 and each of the
remaining three numbers is decreased by 4, then the new average is
(1) 35 (2) 34
(3) 31 (4) 30
(SSC CHSL DEO & LDC Exam.
11.12.2011 (Ist Sitting (Delhi Zone)
12. The mean weight of 34 students
of a school is 42 kg. If the weight
of the teacher be included, the
mean rises by 400 grams. Find
the weight of the teacher (in kg).
(1) 55 kg (2) 57 kg
(3) 66 kg (4) 56 kg
(SSC CHSL DEO & LDC Exam.
21.10.2012 (Ist Sitting)
13. If the mean of 4 observations is
20, when a constant ‘C’ is added
to each observation, the mean
becomes 22. The value of C is :
(1) 6 (2) –2
(3) 2 (4) 4
(SSC CHSL DEO & LDC Exam.
21.10.2012 (IInd Sitting)
14. The average weight of 40 children of a class is 36.2 kg.
When three more children
with weight 42.3 kg, 39.7 kg
and 39.5 kg join the class, the
average weight of the 43 children in the class is
(1) 39.2 kg (2) 36.5 kg
(3) 38.35 kg (4) 37.3 kg
(SSC Delhi Police S.I. (SI)
Exam. 19.08.2012)
15. In a class, the average score of
girls in an examination is 73 and
that of boys is 71. The average
score for the whole class is 71.8.
Find the percentage of girls.
(1) 40% (2) 50%
(3) 55% (4) 60%
(SSC Multi-Tasking (Non-Technical)
Staff Exam. 27.02.2011)
ANSWER:
1. (4) 2. (2) 3. (3) 4. (3)
5. (3) 6. (1) 7. (4) 8. (2)
9. (3) 10. (3) 11. (3) 12. (4)
13. (3) 14. (2) 15. (1)
