# Averages Problems for SSC CGL

1.

What is the average of first 21 multiples of 7?

A.) 49
B.) 77
C.) 66
D.) 57

Required average  = 7(1+2+....+21) / 21
(7/21)X ( (21x22) / 2 )  (because sum of first 21 natural numbers)
= 77 2.

What is the average of first 21 multiples of 7?

A.) 49
B.) 77
C.) 66
D.) 57

Required average  = 7(1+2+....+21) / 21
(7/21)X ( (21x22) / 2 )  (because sum of first 21 natural numbers)
= 77 3.

In a class, the average age of 30 boys is 13 years and the average of 20 girls is 12 years. what is the average age of the whole class?

A.) 12.5 Yrs
B.) 14.2 Yrs
C.) 12.3 Yrs
D.) 12.6 Yrs

Total age of 50 students
(30X 13+20 X 12) = 630
Average =  630/50 = 12.6 Years 4.

In a class, the average age of 30 boys is 13 years and the average of 20 girls is 12 years. what is the average age of the whole class?

A.) 12.5 Yrs
B.) 14.2 Yrs
C.) 12.3 Yrs
D.) 12.6 Yrs

Total age of 50 students
(30X 13+20 X 12) = 630
Average =  630/50 = 12.6 Years 5.

The average age of a class of 32 students is 16 yrs. if the teacher's age is also included, the average increases by one year. Find the age of the teacher

A.) 49
B.) 48
C.) 47
D.) 50

Total age of students is 32 × 16 = 512 Years
Total age inclusive of teacher = 33 × (16+1) = 561
So, Teacher's age is 561-512 = 49 Yrs
There is a shortcut for these type of problems
Teacher's age is 16+(33 × 1) = 49 Years 6.

The average age of a class of 32 students is 16 yrs. if the teacher's age is also included, the average increases by one year. Find the age of the teacher

A.) 49
B.) 48
C.) 47
D.) 50

Total age of students is 32 × 16 = 512 Years
Total age inclusive of teacher = 33 × (16+1) = 561
So, Teacher's age is 561-512 = 49 Yrs
There is a shortcut for these type of problems
Teacher's age is 16+(33 × 1) = 49 Years 7.

The average of seven numbers is 18. The average of first three numbers is 14 and the average of last three numbers is 19. What is the middle number?

A.) 42
B.) 57
C.) 27
D.) None of these

The total of seven numbers = 7 × 18 = 126
The total of first 3 and last 3 numbers is = 3 × 14+3 × 19 = 99
So, the middle number is (126 - 99 ) = 27 8.

The average of seven numbers is 18. The average of first three numbers is 14 and the average of last three numbers is 19. What is the middle number?

A.) 42
B.) 57
C.) 27
D.) None of these

The total of seven numbers = 7 × 18 = 126
The total of first 3 and last 3 numbers is = 3 × 14+3 × 19 = 99
So, the middle number is (126 - 99 ) = 27 9.

Average of five consecutive even numbers is 35. Find the greatest number in these five numbers?

A.) 31
B.) 33
C.) 39
D.) 36

10.

Average of five consecutive even numbers is 35. Find the greatest number in these five numbers?

A.) 31
B.) 33
C.) 39
D.) 36

11.

Average of 13 results is 65. If the average of first six results is 61 and average of last six results is 59 Then find the seventh result?

A.) 115
B.) 135
C.) 125
D.) 105

12.

Average of 13 results is 65. If the average of first six results is 61 and average of last six results is 59 Then find the seventh result?

A.) 115
B.) 135
C.) 125
D.) 105

13.

The average weight of a class of 20 boys was calculated to be 58.4 kgs and it was later found that one weight was misread as 56 kg instead of 65 kg. What is the correct weight?

A.) 67.4kg
B.) 57.75kg
C.) 58.85kg
D.) 49.4kg

Actual total weight is (20 × 58.4 - 56 + 65) = 1177 Kgs
Actual average weight is 1177/20 = 58.85kgs 14.

The average weight of a class of 20 boys was calculated to be 58.4 kgs and it was later found that one weight was misread as 56 kg instead of 65 kg. What is the correct weight?

A.) 67.4kg
B.) 57.75kg
C.) 58.85kg
D.) 49.4kg

Actual total weight is (20 × 58.4 - 56 + 65) = 1177 Kgs
Actual average weight is 1177/20 = 58.85kgs 15.

The average of 10 numbers is 25. The average of first three numbers is 22 1/3 and that of next five is 15 1/5. If the eighth be less than the ninth and tenth numbers by 5 and 11 respectively, then the tenth number is:

A.) 29
B.) 21
C.) 41
D.) 30

16.

The average of 10 numbers is 25. The average of first three numbers is 22 1/3 and that of next five is 15 1/5. If the eighth be less than the ninth and tenth numbers by 5 and 11 respectively, then the tenth number is:

A.) 29
B.) 21
C.) 41
D.) 30

17.

The average of 5 consecutive numbers is n. if the next two number are also included. The average will?

A.) Remain the same
B.) Increase by 1
C.) Increase by 2
D.) Decrease by 1

18.

The average of 5 consecutive numbers is n. if the next two number are also included. The average will?

A.) Remain the same
B.) Increase by 1
C.) Increase by 2
D.) Decrease by 1

19.

The average of marks of a student of 8 exams was 35. How many marks must be get in the next exam so as to increase his average of marks by 5?

A.) 75
B.) 80
C.) 83
D.) 79

20.

The average of marks of a student of 8 exams was 35. How many marks must be get in the next exam so as to increase his average of marks by 5?

A.) 75
B.) 80
C.) 83
D.) 79

21.

If the average age of six numbers is 30. If one is excluded. The average become 25. The excluded number is:

A.) 54
B.) 55
C.) 53
D.) 45

22.

If the average age of six numbers is 30. If one is excluded. The average become 25. The excluded number is:

A.) 54
B.) 55
C.) 53
D.) 45

23.

Of the three numbers whose average is 45, the first is half of the sum of the others. The first number is:

A.) 45
B.) 51
C.) 59
D.) 49

24.

Of the three numbers whose average is 45, the first is half of the sum of the others. The first number is:

A.) 45
B.) 51
C.) 59
D.) 49

25.

The average age of father and his two sons is 27 Years. Five years ago, the average age of the two sons was 12 Years. If the difference between the ages of the two sons is four years, what is the present age of the father?

A.) 42
B.) 47
C.) 48
D.) 49

The total present age of father and two sons is 3S27 = 81 yrs
The total present age of sons is (12+5) X 2 = 34Years
so, present age of father is 81 - 34 = 47 yrs 26.

The average age of father and his two sons is 27 Years. Five years ago, the average age of the two sons was 12 Years. If the difference between the ages of the two sons is four years, what is the present age of the father?

A.) 42
B.) 47
C.) 48
D.) 49

The total present age of father and two sons is 3S27 = 81 yrs
The total present age of sons is (12+5) X 2 = 34Years
so, present age of father is 81 - 34 = 47 yrs 27.

There were 45 students in a hostel, if the numbers of students increased by 7, the expenses of the mess were increased by Rs. 39 per day while the average expenditure per head diminished by Re.1. What is the original expenditure of the mess?

A.) Rs. 562
B.) Rs. 624
C.) Rs. 1950
D.) Rs. 585

Let the original expenditure be Rs.x
Original average expenditure = X/45
New average expenditure = (x+39)/52
So (x/45) - ((x+39) / 52) = 1  so x = 585
so, original expenditure is Rs 585 28.

There were 45 students in a hostel, if the numbers of students increased by 7, the expenses of the mess were increased by Rs. 39 per day while the average expenditure per head diminished by Re.1. What is the original expenditure of the mess?

A.) Rs. 562
B.) Rs. 624
C.) Rs. 1950
D.) Rs. 585

Let the original expenditure be Rs.x
Original average expenditure = X/45
New average expenditure = (x+39)/52
So (x/45) - ((x+39) / 52) = 1  so x = 585
so, original expenditure is Rs 585 29.

Of three numbers, the third is twice the second and the second is 4 times the first. If their average is 78, the smallest of the three numbers is:

A.) 15
B.) 21
C.) 17
D.) 18

Let first number be x.
So,2nd no. = 4x & 3rd no.=8x.
So,x+4x+8x=78 × 3 = 234.
13x = 234
x = 234/13
Hence,smallest Number x=18. 30.

Of three numbers, the third is twice the second and the second is 4 times the first. If their average is 78, the smallest of the three numbers is:

A.) 15
B.) 21
C.) 17
D.) 18

Let first number be x.
So,2nd no. = 4x & 3rd no.=8x.
So,x+4x+8x=78 × 3 = 234.
13x = 234
x = 234/13
Hence,smallest Number x=18. 31.

If the average of seven numbers is 35. If one is included. The average become 40. The included number is:

A.) 70
B.) 75
C.) 65
D.) 80

32.

If the average of seven numbers is 35. If one is included. The average become 40. The included number is:

A.) 70
B.) 75
C.) 65
D.) 80

33.

Out of 12 employs of a bank, one employ retires and his place, a new employ of age 24 years joins as a result average age of employs reduces by 4 years. The age of the retired employ is:

A.) 72
B.) 62
C.) 64
D.) 71

34.

Out of 12 employs of a bank, one employ retires and his place, a new employ of age 24 years joins as a result average age of employs reduces by 4 years. The age of the retired employ is:

A.) 72
B.) 62
C.) 64
D.) 71

35.

A man covered a certain distance at a speed of 8 Kmph and returned at a speed of 4 Kmph. Find the average speed of whole journey?

A.) 3 ¾ Kmph
B.) 5 1/3 Kmph
C.) 4 ¼ Kmph
D.) 2 ¼ Kmph

36.

A man covered a certain distance at a speed of 8 Kmph and returned at a speed of 4 Kmph. Find the average speed of whole journey?

A.) 3 ¾ Kmph
B.) 5 1/3 Kmph
C.) 4 ¼ Kmph
D.) 2 ¼ Kmph

37.

The average of first five odd numbers is?

A.) 5
B.) 4
C.) 4.5
D.) 5.2

38.

The average of first five odd numbers is?

A.) 5
B.) 4
C.) 4.5
D.) 5.2

39.

The average temperature for Monday, Tuesday and Wednesday was 41 c. the average temperature for Tuesday, Wednesday and Thursday was 42 c. If the temperature on Thursday be 43 c, what was the temperature on Monday?

A.) 41 c
B.) 39 c
C.) 40 c
D.) 42 c

40.

The average temperature for Monday, Tuesday and Wednesday was 41 c. the average temperature for Tuesday, Wednesday and Thursday was 42 c. If the temperature on Thursday be 43 c, what was the temperature on Monday?

A.) 41 c
B.) 39 c
C.) 40 c
D.) 42 c

41.

A man spends Rs. 1600 per month on an average for the first three months, Rs 1550 for next four months and Rs. 1800 per month for the last five months and saves Rs . 5200 a year. What is his average monthly income?

A.) Rs. 2050
B.) Rs. 2100
C.) Rs. 1950
D.) Rs. 2200

Total expenditure for the first 3 months = 3 × 1600 = 4800
Total expenditure for 4 months = 4 × 1550 = 6200
Total expenditure for 5 months = 5 × 1800 = 9000
Total expenditure and saving (which is income for one year)
= 4800 + 6200 + 9000 + 5200 = Rs. 25200
So, Average monthly income = 25200/12  =  Rs. 2100 42.

A man spends Rs. 1600 per month on an average for the first three months, Rs 1550 for next four months and Rs. 1800 per month for the last five months and saves Rs . 5200 a year. What is his average monthly income?

A.) Rs. 2050
B.) Rs. 2100
C.) Rs. 1950
D.) Rs. 2200

Total expenditure for the first 3 months = 3 × 1600 = 4800
Total expenditure for 4 months = 4 × 1550 = 6200
Total expenditure for 5 months = 5 × 1800 = 9000
Total expenditure and saving (which is income for one year)
= 4800 + 6200 + 9000 + 5200 = Rs. 25200
So, Average monthly income = 25200/12  =  Rs. 2100 43.

The average temperature for Monday, Tuesday and Wednsday is 36.3 degrees C. The average temperature for Tuesday, Wednesday and Thursday is 36.7 degrees C. if Monday's temperature recorded as 39 degrees c, find the Thursday's temperature ?

A.) 40.2º C
B.) 40.4º C
C.) 41.4º C
D.) 39.2º C

MOn + Tue + wed Temperature  =  3 × 36.3 = 108.9
Tue + wed Temperature = 108.9 - 39 = 69.9
Tue + wed + Thu temperature = 3 × 36.7 = 110.1
So, Thursday's temperature = 110.1 - 69.9 = 40.2º C 44.

The average temperature for Monday, Tuesday and Wednsday is 36.3 degrees C. The average temperature for Tuesday, Wednesday and Thursday is 36.7 degrees C. if Monday's temperature recorded as 39 degrees c, find the Thursday's temperature ?

A.) 40.2º C
B.) 40.4º C
C.) 41.4º C
D.) 39.2º C

MOn + Tue + wed Temperature  =  3 × 36.3 = 108.9
Tue + wed Temperature = 108.9 - 39 = 69.9
Tue + wed + Thu temperature = 3 × 36.7 = 110.1
So, Thursday's temperature = 110.1 - 69.9 = 40.2º C 45.

The average age of a college is 21.8 years. If the average age of students of college is 24.2 years and Average age of lecturers of college is 20.6 years. Find the ratio of the number of students to that of Lecturers?

A.) 2:1
B.) 2:3
C.) 3:2
D.) 1:2

46.

The average age of a college is 21.8 years. If the average age of students of college is 24.2 years and Average age of lecturers of college is 20.6 years. Find the ratio of the number of students to that of Lecturers?

A.) 2:1
B.) 2:3
C.) 3:2
D.) 1:2

47.

Six years ago the average of a family of 4 members was 26 years. A child has been born, due to Which the average age of the family is 24 years today. What is present age of the child?

A.) 4years
B.) 6years
C.) 8years
D.) 5years

48.

Six years ago the average of a family of 4 members was 26 years. A child has been born, due to Which the average age of the family is 24 years today. What is present age of the child?

A.) 4years
B.) 6years
C.) 8years
D.) 5years

49.

A man's daily expenditure isRs. 11 during April, Rs. 15 during March and Rs. 17 during Feb. Find the average daily expenditure for the three months (it is a leap year)?

A.) Rs. 14.20
B.) Rs. 14.30
C.) Rs. 14.4
D.) Rs. 14.31

50.

A man's daily expenditure isRs. 11 during April, Rs. 15 during March and Rs. 17 during Feb. Find the average daily expenditure for the three months (it is a leap year)?

A.) Rs. 14.20
B.) Rs. 14.30
C.) Rs. 14.4
D.) Rs. 14.31