Averages (200 Questions with Explanation): Quantitative Aptitude Test

  • Chicken Fry Biryani

  • Averages
  • 21. 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

Answer: Option 'B'

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

  • 22. 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

Answer: Option 'A'

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

  • 23. 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

Answer: Option 'D'

1:2

  • 24. 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

Answer: Option 'C'

8 years

  • 25. 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

Answer: Option 'B'

Rs. 14.30

  • 26.  In a class of 18 students in an examination in science 1 student scored 100 marks, 2 get zero each and the average oh the rest was 45. What is the average of the whole class? 
   A.) 41
   B.) 43
   C.) 42
   D.) 44

Answer: Option 'B'

43

  • 27. The average weight of 8 persons increases by 1.5kg when a person weighting 65kg is replaced by a new person. What could be the weight of the new person?
   A.) 53kg
   B.) 58.85kg
   C.) 75kg
   D.) 77kg

Answer: Option 'D'

Let the average weight of 8 persons be 'x'
years and the age of the new person be 'y' years
so, (8x - 65 + y) / 8  = x+1.5
so, y = 77kgs
65 + 8X1.5 = 77kgs

  • 28.  In a hostel of 12 boys and some girls, an average consumption of rice per month is 12 kg, while the Average consumption for boys is 16 kg per head and for girls 8 kg per head. The number of girls in The hostel? 
   A.) 11
   B.) 12
   C.) 12
   D.) 13

Answer: Option 'C'

Number of girls --- G 
12+G) × 12 = (12 × 16)+(8 × G) 
144 + 12G = 192 + 8G 
12G − 8G = 192 − 144 
4G = 48 
G = 12.

  • 29. A family consists of two grandparents, two parents and three grandchildren. The average age of the grandparents is 67 years, that of the parents is 35 years and that of the grandchildren is 6 years. What is the average age of the family? 
   A.) 28 ( 4 / 7 ) years
   B.) 31 ( 5 / 7) years
   C.) 32 ( 1 / 7 ) years
   D.) Cannot be determined

Answer: Option 'B'

Given
The family consists of two grandparents, two parents and three grandchildren
The average age of two grandparents = 67 years.
=> Total age of two grandparents = (67 * 2) = 134 years
The average age of two parents = 35 years
=> Total age of two parents = (35 * 2) = 70 years
The average age of three grand children = 6 years.
=> Total age of three grand children = (6 * 3) = 18 years.
Required Average age of the family = Total age of (two grandparents + two parents + three grand children) / Total members in the family
= ( 134 + 70 + 18 ) / (2 + 2 + 3)
= 222 / 7
= 31 (5 / 7) years

  • 30. If 13:11 is the ratio of present age of Jothi and Viji respectively and 15:9 is the ratio between Jothi's age 4 years hence and Viji's age 4 years ago. Then what will be the ratio of Jothi's age 4 years ago and Viji's age 4 years hence?
   A.) ( 15 : 9)
   B.) ( 9 : 5 )
   C.) (11 : 13)
   D.) ( 12:15)

Answer: Option 'C'

Let the present age of Jothi and Viji be 13X and 11X respectively.
Given, Jothi's age 4 years hence and Viji's age 4 years ago in the ratio 15:9.
That is, (13X + 4) / (11X - 4) = 15 / 9
=> 9 (13X + 4) = 15 (11X - 4)
=> 117X + 36 = 165X - 60
=> 165X - 117X = 60 + 36
=> 48X = 96
=> X = 96 / 48
=> X = 2
Now, Required ratio = (13X - 4) / (11X + 4)
on substituting value of X = 2 we get,
= [13(2)-4] / [11(2)+4]
= 22/26
11/13
Hence the answer is 11:13