Aptitude - Averages Online Quiz



Following quiz provides Multiple Choice Questions (MCQs) related to Averages. You will have to read all the given answers and click over the correct answer. If you are not sure about the answer then you can check the answer using Show Answer button. You can use Next Quiz button to check new set of questions in the quiz.

Questions and Answers

Q 1 - What is the average of first 9 multiples of 3?

A - 15

B - 20

C - 25

D - 30

Answer : A

Explanation

Average = (3+6+9+12+15+18+21+24+27)/ 9= 135/9 = 15

Q 2 - 68 is the average score scored by the student in a class. 80 is the average of girls marks and 60 is the average score of boys in this class. Find out the percentage of boys in the class?

A - 20%

B - 40%

C - 50%

D - 60%

Answer : D

Explanation

If 100 is the total quantity of the class and x is the number of boys in the class , then the number  of girls will be (100-x).
60x+ 80(100-x) = 6800  ⇒ 60x+8000-80x = 6800
= 20x = 1200 ⇒ x =60
 So , its proves that that boys percentage in a class is 60%.

Q 3 - A man have 65 kg weight in group if this person interchange with new person then the average weight of 8 man expended by 1.5 kg . What should be the weight of that new man?

A - 77 kg

B - 45 kg

C - 23 kg

D - 67 kg

Answer : A

Explanation

Weight increase = 1.5*8 = 12 kg.
With the help of this  increase weight we find that the weight of the new men is (65+12)= 77.

Q 4 - What should be the age difference between new man and the old members if interchange with new men with old men then the average age of 5member as he was before the period of 3 year has no change at the present time?

A - 15 years

B - 17 years

C - 18 years

D - 20 years

Answer : A

Explanation

Sum of the increment during the period of 3 years =(5*3) = 15 Years.
∴  old and new man have the age difference between them = 15 years.

Q 5 - With the average of 12.4 takes 5 wickets by use of 26 run. A player has 0.4 downfalls in his average. What should be the number of wicket taken by him before the last match played?

A - 85

B - 23

C - 45

D - 67

Answer : A

Explanation

x is the number of wickets taken a player  before the last match played.
Then, (12.4x+26)/(x+5) =12 ⇒ 12.4x+26 =12x+60 ⇒ 0.4x =34
⇒ 0.4x =34 ⇒ x= 34/0.4 ⇒ x =340/4 = 85.
Wickets required = 85.

Q 6 - 555 is the sum of 5 numbers. What should be the last numbers if average of two numbers is 75 and last 3 numbers have average of 115?

A - 145

B - 150

C - 155

D - 160

Answer : A

Explanation

If a and b is the last two numbers. then,
 (75*2)+115+(a+b)= 555 ⇒(a+b)= 555-365= 290
 Average of last two numbers = 290/2 = 145

Q 7 - The average of six numbers is 3.95. The average of two of them is 3.4, while the average of the other two is 3.85. What is the average of the remaining two numbers?

A - 4.5

B - 4.6

C - 4.7

D - 4.8

Answer - B

Explanation

Sum of the remaining two numbers = (3.95 x 6) - [(3.4 x 2) + (3.85 x 2)] = 23.70 - (6.8 + 7.7) = 23.70 - 14.5 = 9.20 
Therefore Required average = 9.22 = 4.6.

Q 8 - The average age of 15 students of a class is 15 years. Out of these, the average age of 5 5 students is 14 years and that of the other 9 students is 16 years. The age of the 15th student is?

A - 11

B - 14

C - 15

D - 16

Answer - A

Explanation

Age of the 15th student = [15 x 15 - (14 x 5 + 16 x 9)] = (225 - 214) = 11 years.

Q 9 - The average weight of a class of 24 students is 35 kg. If the weight of the teacher be included, the average rises by 400g. The weight of the teacher is:?

A - 50

B - 45

C - 53

D - 55

Answer - B

Explanation

Weight of the teacher = (35.4 x 25 - 35 x 24)kg = 45 kg

Q 10 The arithmetic mean of the scores of a group of students in a test was 52. The brightest 20% of them secured a mean score of 80 and the dullest 25% a mean score of 31. The mean score of remaining 55% is?

A - 51.4

B - 50

C - 54

D - 45

Answer - A

Explanation

Let the required mean score be z. Then, 

20 x 80 + 25 x 31 + 55 x z = 52 x 100 
1600 + 775 + 55z = 5200 

55z = 2825 = x - 51.40
aptitude_averages.htm
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