Average
Team Careers360, 18 Sep 2019

Average - The average is the central value of any given data. It is also known as the mean of any data. The average is an important chapter from the exam point of view. In exams like SSC , there are 2-3 questions asked from this chapter every year. It is a conceptual topic which can be without using pen-paper and just by having a glance over the question. This topic is usually asked in other exams like CAT, GMAT, GRE as there is at least 1 question from average in the exam.

The general mathematical Average formula is as follows:

Average= Sum of the observations/Total number of observations

Let’s us understand the concept of averages by using the following observations:-

When a person is joining the group

Statement

Interpretation of the statements

  • If average remain the same

The number brought by Person = Average of the group(before his joining)

  • If the average Increases

It means the person who joined have brought the more amount then the group’s average

  • If the average Decreases

It means the person who joined have brought the less amount then the group’s average


When a person is leaving the group

Statement

Interpretation of the statements

  • If average remain the same

The number with Person left the group = old average = New average

  • If the average Increases

It means the person leaving with a lower amount than their average(when he was in the group)

  • If the average Decreases

It means the person leaving with a higher number than their average(when he was in the group)


When a person is replaced by another person

Statement

Interpretation of the statements

  • If average remain the same

It means the amount brought by the person who left the group = amount by the person who joined

  • If the average Increases

It means the person who joined came with a higher amount than that of the person who left.

  • If the average Decreases

It means the person who joined came with a lower amount than that of the person who left.


How to prepare averages?

  • The simple tricks can be used to solve the questions of averages.

  • Keep the basic clear which can benefit while solving the problems.

  • You can also use formulas to solve the questions.

  • Go through the previous questions as they get repeated with a little refurbishment.

  • Take online test related to the topic to be aware of the trending pattern in the examinations.

Q 1. The average of the first five multiples of 3 is:

  1. 3

  2. 9

  3. 12

  4. 15

  5. None of these

View Solution


Q 2. The average height of 30 boys out of a class of 50 is 160 cm. If the average height of the remaining boys is 165 cm, the average height of the whole class (in cm) is:

  1. 161

  2. 162

  3. 163

  4. 164

  5. None of these

View Solution


Q 3. The average of three numbers is 20. If the two numbers are 16 and 22, the third number is:

  1. 22

  2. 20

  3. 19

  4. 18

  5. None of these

View Solution


Q 4. The average of five results is 46 and that of the first four is 45. The fifth result is:

  1. 1

  2. 10

  3. 12.5

  4. 50

  5. None of these

View Solution


Q 5. The average of Radhika’s marks in 7 subjects is 75. His average in six subjects excluding science is 72. How many marks did he get in Science?

  1. 72

  2. 90

  3. 93

  4. None of these

  5. 95

View Solution


Q 6. The average of eight numbers is 14.. The average of six of these numbers is 16. The average of the remaining two numbers is:

  1. 4

  2. 8

  3. 16

  4. Data inadequate

  5. 32

View Solution


Q 7. A classroom has equal number of boys and girls. Eight girls left to play Kho-Kho, leaving twice as many boys as girls in the classroom. What was the total number of girls and boys present initially?

  1. 22

  2. 24

  3. 32

  4. None of these

  5. 16

View Solution


Q 8. On Children Day, sweets were to be equally distributed among 175 children in a school. Actually on the Children’s Day, 35 children were absent and therefore each child got 4 sweets extra. Total how many sweets were available for distribution?

  1. 2400

  2. 2500

  3. 2600

  4. None of these

  5. 2480

View Solution


Q 9. The average price of three items of furniture is Rs. 15000. If their prices are in the ratio 3:5:7, the price of the cheapest item is:

  1. R9000

  2. R15000

  3. R16000

  4. R21000

  5. R18000

View Solution


Q 10. Of three numbers, second is twice the first and is also thrice the third. If the average of the three numbers is 44, the largest number is:

  1. 24

  2. 56

  3. 72

  4. 108

  5. 36

View Solution


Q 11. The average of ten numbers is 7. If each number is multiplied by 12, then the average of new set of numbers is:

  1. 50

  2. 19

  3. 82

  4. 84

  5. 7

View Solution


Q 12. The mean of 100 observations was calculated as 40. It was found later on that one of the observations was misread as 83 instead of 53. The correct mean is:

  1. 39

  2. 39.7

  3. 40.3

  4. 37

  5. 42.7

View Solution


Q 13. The average of six numbers is 30. If the average of first four is 25 and that of last three is 35, the fourth number is:

  1. 25

  2. 50

  3. 35

  4. 40

  5. 30

View Solution


Q 14. A person starting from his house covers a distance at 15 km/hr and returns to the starting place at 10 km/hr. His average speed during whole journey is

  1. 11 km/hr

  2. 12 km/hr

  3. 7\frac{1}{2}km/hr

  4. 10 km/hr

  5. 13 km/hr

View Solution


Q 15. 3 person A, B and C covers a distance at 10 km/hr ,12 km/hr and 15 km/hr. the average speed is:

  1. 11 km/hr

  2. 12 km/hr

  3. 9 km/hr

  4. 14 km/hr

  5. 7 km/hr

View Solution


Q 16. The average age of 24 boys and the teacher is 15 years. When the teacher’s age is excluded, the average decreases by 1. What is the age of the teacher?

  1. 38 years

  2. 39\: years

  3. 30 \:years

  4. Data inadequate

  5. 40\: years

View Solution


Q 17. The average salary per month of 30 employees in a company is Rs. 4000. If the manager’s salary is added, the average salary increases to Rs. 4300, what is the salary of the manager?

  1. Rs. 10000

  2. Rs. 12500

  3. Rs. 12000

  4. Rs. 13300

  5. Rs. 13000

View Solution


Q 18. The average age of 30 students is 9 years. If the age of their teacher is included, it becomes 10 years. The age of the teacher (in years) is:

  1. 30

  2. 31

  3. 35

  4. 40

  5. 27

View Solution


Q 19. The average age of 40 students of a class is 15 years. When 10 new students are admitted, the average is increased by 0.2 years. The average age of new students is:

  1. 15 years

  2. 16 years

  3. 16.2 years

  4. 16.4 years

  5. 15.2 years

View Solution


Q 20. The average weight of 8 men is increased by 1.5 kg when one of the men who weighs 65 kg is replaced by a new man. The weight of the new man is:

  1. 76 kg

  2. 76.5 kg

  3. 77.8 kg

  4. 77 kg

  5. 76.7 kg

View Solution


Q 21. The average weight of 6 men decreases by 3 kg when one of them weighing 80 kg is replaced by a new man. The weight of the new man is:

  1. 6 kg

  2. 58 kg

  3. 62 kg

  4. 60 kg

  5. 76 kg

View Solution


Q 22. The average age of a committee of eight members is 40 years. A member aged 55 years retired and his place was taken by another member aged 39 years. The average age of the present committee is:

  1. 39 years

  2. 38 years

  3. 36 years

  4. 37 years

  5. 35 years

View Solution


Q 23. A cricketer has a certain average for 9 innings. In the tenth innings, the score is 100 runs, thereby increasing his average by 8 runs. His new average is:

  1. 20 runs

  2. 24 runs

  3. 28 runs

  4. 23 runs

  5. 32 runs

View Solution


Q 24. A man takes 5 hours to walk to a certain place and returns by car. He would have, however, gained 3 hours if he had completed his entire journey by car. How long would he have taken to walk both ways?

  1. 5 hours

  2. 6.5 hours

  3. 7 hours

  4. 8 hour

  5. 6 hours

View Solution


Q 25. A man whose bowling average is 12.4 takes 5 wickets for 26 runs and thereby decreases his average by 0.4. The number of wickets, taken by him before his last match is:

  1. 85

  2. 78

  3. 72

  4. 70

  5. 64

View Solution

Preparation
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