Averages

Q.

The average weight of a group of 8 people increases by 2.5 kg when a new person replaces one of them who weigh 65 kg. What might be the weight of the new person?

1. 80

2. 90

3. 95

4. 91

5. 85

Q. A batsman in his 17th innings, makes a score of 85 runs, and thereby, increases his average by 3 runs. What is his average after the 17th innings? He had never been 'not out'.

1. 37
2. 39
3. 43
4. 47
5. None of these

Q. The average of 50 numbers is 38. If two numbers 45 and 55 are discarded, the average of the remaining set of numbers is:

1. None of these
2. 38.5
3. 37.5
4. 37
5. 36.5

Q. Ten years ago, the ages of members of a joint family of eight people added up to 231 years. Three years later, one member died at the age of 60 years and a child was born in the same year. After another three years, one more member died, again at 60, and a child was born during the same year. The current average age of this eight member joint member is nearest to?

1. 22 years
2. 21 years
3. 25 years
4. 24 years

Q. The average of marks obtained in 120 students was 35. If average of passed candidates was 39 and that of failed candidates is 15, the numbers of candidates who passed the examinations is

1. 110
2. 100
3. 120
4. 80
5. None of these

Q. A team of 8 persons joins a shooting competition. The best marksman scored 85 points. If he had scored 92 points, then the average score for the team would have been 84. The number of points the team scored was

1. 645
2. 558
3. 672
4. None of these
5. 665

Q. The total marks obtained by a student in Physics, Chemistry and Mathematics together is 120 more than the marks obtained by him in Chemistry. What are the average marks obtained by him in Physics and Mathematics together?

1. 60
2. 120
3. 40
4. Cannot be determined
5. None of these

Q. The average age of the family of five members is 24. If the present age of the youngest member is 8 yr, then what was the average age of the family at the time of the birth of the youngest member?

1. 21 yr
2. 20 yr
3. 12 yr
4. 16 yr
5. 18 yr

Q.

A dairyman pays Rs. 6.40 per litre of milk. He adds water and sells the mixture at Rs. 8 per litre, thereby making 37.5% profit. The proportion of water to milk received by the customers is:

1. 1 : 20

2. 1 : 19

3. 1 : 10

4. 1 : 15

5. 1 : 12

Q. The average of a, b and c is 79 and the average of a and c is also 79. Then the value of b is:

1. none of these
2. 0
3. 79
4. -79

Q.

Karan's marks were incorrectly entered as 83 instead of 63. Due to that the average marks for the class got increased by $\frac{1}{2}$. The number of pupils in the class is:

1. 30

2. 40

3. 50

4. 60

5. 90

Q.

The average of five consecutive odd natural numbers is 61. What is the difference between the highest and lowest numbers?

1. 7

2. 8

3. 4

4. 6

5. 2

Q. Three Maths classes; X, Y, and Z take an algebra test.
The average score in class X is 83.
The average score in class Y is 76.
The average score in class Z is 85.
The average score of all students in class X and Y together is 79.
The average score of all students in classes Y and Z together is 81.
What is the average of all the three classes?

1. 84.5
2. 81.5
3. 82
4. 81

Q.

The average salary of all the employees in a company is Rs.8000. The average salary of 7 technicians is Rs.12000 and the average salary of the rest is Rs.6000. The total number of workers in the company is:

1. 21

2. 22

3. 23

4. 24

5. 20

Q.

The average age of a family of 6 members is 24 years. If the age of the youngest member be 6 years, then what was the average age of the family member at the birth of the youngest member (in years)?

1. 21.6

2. 20.5

3. 21

4. 22

5. 22.6

Q. The average of 5 numbers is 306.4. The average of the first two numbers is 431 and the average of the last two numbers is 214.5. What is the third number?

1. 108
2. 52
3. 321
4. None of the above
5. Cannot be determined

Q. The average weight of a class of 20 students is 45 kgs. A new student whose weight is 40 kgs replaces an old student of this class. Hence, the average weight of the whole class decreases by 1 kg. The weight of the replaced student is :

1. none of these
2. 55 kgs
3. 60 kgs
4. 50 kgs

Q.

Find the average of all the odd numbers and average of all the even numbers from 1 to 45.

1. 23 and 25
2. 23 and 24
3. 25 and 26
4. 20 and 21
5. 23 and 23

Q.

The average age of the students of a class is 15.8 years. The average age of boys in the class is 16.4 years and that of the girls is 15.4 years.
What is the ratio of the number of girls to the number of boys in the class?

1. 5:2

2. 3:2

3. 2:1

4. 2:5

5. 2:3

Q. The sum of 8 consecutive odd numbers is 656. Also, the average of four consecutive even numbers is 87. What is the sum of the smallest odd number and the second largest even number?

1. 175
2. 163
3. None of these
4. Cannot be determined
5. 165

Q.

The average run of a cricket player in 10 innings was 32. How many runs must he make in his next innings so as to increase his average of runs by 4?

1. 72

2. 84

3. 76

4. 86

5. 80

Q. The average of first five multiples of 3 is :

1. 9
   
2. 15
   
3. 12
   
4. 3
   
5. None of these

Q. A batsman has a certain average of runs for 12 innings. In the 13th innings, he scores 96 runs and thereby increasing his average by 5 runs. What is his average after the 13th innings?

1. 48
2. 36
3. 64
4. 72
5. None of these

Q.

A family consists of two grandparents, two parents and three grandchildren. The average age of the grandparents is 68 years, that of the parents is 36 years and that of the grandchildren is 8 years. The average age of the family is:

1. 33(1/7)

2. 31(5/7)

3. 34(3/7)

4. 36(3/7)

5. 34(2/7)

Q. The average monthly expenditure of a family for the first four months is Rs. 2750, for the next three months is Rs. 2940, and for the last five months Rs. 3130. If the family saves Rs. 5330 throughout year, find the average monthly income of the family for that year.

1. Rs. 3800
2. Rs. 3500
3. Rs. 3400
4. Rs. 4200
5. None of these

Q.

What is the average sale of all the branches (in thousands numbers) for the year 2000?

1. 73.333

2. 80.667

3. 79.167

4. 88.133

5. 96

Q. The mean weight of 34 students of a school is 42 kg. If the weight of the
teacher is included, then the mean rises by 400 g. Find the weight (in kg) of the teacher.

1. 66
2. 56
3. 57
4. None of these
5. 55

Q.

Karan buys petrol at Rs.8, Rs.7.50 and Rs.8.50 per litre for three successive years. What is the approximate average cost per litre of petrol if he spends Rs.4000 on petrol each year?

1. 7.68

2. 7.98

3. 8.28

4. 8.84

5. 7.88

Q.

If the average marks of three sections of 55, 60 and 45 students respectively is 50, 55, 60, then the average marks of all the students is:

1. 53.50

2. 54.68

3. 56.60

4. 58.60

5. 55.50

Q.

The average weight of 3 men A, B and C is 84 kg. Another man D joins the group and the average now becomes 80 kg. If another man E, whose weight is 3 kg more than that of D, replaces A, then the average weight of B, C, D and E becomes 79 kg. The weight of A is:

1. 70

2. 75

3. 76

4. 74