Questions on Average Practice Test Sample Paper - 1 with Answer Key and Solution [Quantitative Aptitude]- Download in PDF

Here is solved questions of problems on Average [quantitative aptitude] for SBI PO and IBPS exams. Problems on finding average related questions are asked in almost all entrance examinations and candidates need to practice this section very hard to score good marks and hence good position in merit list. You can also download this question paper in PDF to save it for future references or take print out.

 

Average [Quantitative Aptitude] Model Test Paper - 1

 

Maximum Marks: 10     /      Duration: 10 Mins

Q.1. The average of first 9 prime numbers is:

A) 9
B) 11
C) 11 1/9
D) 11 2/9
E) None of these

Explanation (Show/Hide)

Average = (2 + 3 + 5 + 7 + 11 + 13 + 17 + 19 + 23) / 9 = 100/9

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Q.2. The average of five consecutive odd numbers is 61. What is the difference between highest and lowest numbers?

A) 2
B) 5
C) 8
D) Cannot be determined
E) None of these

Explanation (Show/Hide)

As average is 61 and number of terms are odd so middle term (3rd) will be 61.
So five consecutive numbers are: 57, 59, 61, 63, 65

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Q.3. The average of five numbers is 27. If one number is excluded, the average becomes 25. The excluded number is:

A) 25
B) 27
C) 30
D) 35
E) None of these

Explanation (Show/Hide)

Sum of all five numbers = 27 * 5 = 135
After excluding a number sum of remaining 4 numbers = 25 * 4 = 100
Hence excluded number = 135 - 100 = 35

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Q.4. The average of six numbers is 395. The average of two of them is 340, while the average of other two is 385. What is the average of the remaining two numbers?

A) 450
B) 460
C) 470
D) 480
E) None of these

Explanation (Show/Hide)

Sum of all six numbers = 395 * 6 = 2370
Sum of first two numbers = 340 * 2 = 680
Sum of other two numbers = 385 * 2 = 770
Sum of remaining two = 2370 - 680 - 770 = 920
Hence average = 920/2 = 460.

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Q.5. The average age of 36 students in a group is 14 years. When teacher's age is included to it, the average increases by one. What is the teacher's age in years?

A) 31 years
B) 36 years
C) 51 years
D) Cannot be determined
E) None of these

Explanation (Show/Hide)

Sum of ages of all students = 36 * 14 = 504
After adding teachers age now there are 37 person's and new average is 15
So sum of ages of all 37 person's = 37 * 15 = 555
Hence teacher's age = 555 - 504 = 51 years.

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Q.6. The average of 50 observations was 36. It was found later that an observation 48 was wrongly taken as 23. The corrected average is:

A) 35.2
B) 36.1
C) 36.5
D) 39.1
E) None of these

Explanation (Show/Hide)

Sum of all 50 observations = 36 * 50 = 1800
As 23 was taken instead of 48 so we will deduct 23 and add 48
So new sum of 50 observations = 1800 - 23 + 48 = 1825.
New average = 1825/36 = 36.5

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Q.7. 3 years age, the average age of a family of 5 members was 17 years. A baby having been born, the average age of the family is the same today. The present age of the baby is

A) 1 years
B) 1 1/2 years
C) 2 years
D) 3 years
E) None of these

Explanation (Show/Hide)

Total age of five members before 3 years = 17 * 5 = 85
Total age of five members now = 85 + 5*3 = 100 years
Total age of six members now = 17 * 6 = 102
Hence age of baby is 102 - 100 = 2 years.

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Q.8. A cricketer has a certain average for 10 innings. In the eleventh inning, he scored 108 runs, thereby increasing his average by 6 runs. His new average is :

A) 48 runs
B) 52 runs
C) 55 runs
D) 60 runs
E) None of these

Explanation (Show/Hide)

Let average of 10 innings = X
His total score in 10 innings = X * 10
After scoring 108 his new total score = X * 10 + 108
His new average = X + 6 = (X*10 + 108)/11
=> X = 42, New average = 42 + 6 = 48.

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Q.9. The average monthly salary of 20 employees in an organization is Rs. 1500. If the manager's salary is added, then the average salary increases by Rs. 100. What is the manager's monthly salary?

A) Rs. 2000
B) Rs. 2400
C) Rs. 3600
D) Rs. 4800
E) None of these

Explanation (Show/Hide)

Total salary of 20 employees = 1500 * 20 = 30000
After adding manager's salary new average = 1600
Now total salary of 21 employees (1 manager + 20 employees ) = 21 * 1600 = 33600
Hence manager's salary = 33600 = 30000 = 3600.

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Q.10. Of the four numbers, whose average is 60, the first is one - fourth of the sum of the last three. The first number is:

A) 15
B) 45
C) 48
D) 60
E) None of these

Explanation (Show/Hide)

Let the numbers be A, B, C and D
A + B + C + D = 60 * 4 = 240......Eq 1
As given in question A = (1/4) (B + C + D)
=> 4A = B + C + D.....Eq 2
From eq 1 and 2: A + 4A = 240
=> A = 48.

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