# 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.

Q 1 - Find the average of the numbers which are as follows : 15, 5, 0, 12, 8

A - 4

B - 6

C - 8

D - 10

### Explanation

`Average required = (15+5+0+12+8)/5 = 40/5 = 8`

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%

### 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 committee have 8 person. If 35 year and 45 year aged lady replaced by two men in that case the average of age become more 2 year in the comparison of old one. Find out the average age of two men?

A - 24

B - 35

C - 54

D - 48

### Explanation

```Age increase  = (2*8) = 16 years.
Total age of two lady  who replaced = (35+45)= 80
Total age of two man  = (80+16) =96
Average age of those men = 96/2 = 48.
Hence, is 48 the required  average age.```

Q 4 - 84 kg is the average weight of 3 people A, B and C. 80 kg is the average if D joins the group. A new man E replaces who have 3kg more weight than D. At that time 79 kg is the average weight of B, C, D and E. What should be the weight of A?

A - 75 kg

B - 34 kg

C - 26 kg

D - 56 kg

### Explanation

```A+B+C= (3*84)= 252 kg.     A+B+C+D= (4*80)= 320 kg
weight of D =( 320- 252) =68 kg.   weight of E = (68+3)= 71 kg.
sum of the weight of B+C+D+E= (79*4)= 316 kg ,
sum of the weight of B+C+D = (316-71)=245kg.
Total weight of A = (320- 245 )= 75 kg.```

Q 5 - 40 year is the average of the class. 32 years is the average of the class if 12 new students also add in this class. Find out the number of students in the class?

A - 15

B - 16

C - 17

D - 12

### Explanation

```x is the strength of the class.
40x+12*32 = 36* (x+12) ⇒ 4x =(432- 384) = 48 ⇒ x = 12
∴ original strength = 12```

Q 6 - Drinks were done by 6 persons. Out of them 5 person paid 32 Rs. each, Rs. 80 more paid by the 6th person in the comparison of average expenditure of all. Find out the total amount paid by 6 persons?

A - Rs 288

B - Rs 290

C - Rs 295

D - Rs 300

### Explanation

```if x is the average  expenditure  of 6 person.
(32*5)+(x+80)= 6x = 5x = (160+80) = 5x= 240 ⇒ x = 48
Total expenditure  = 48*6  =288 Rs.```

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

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 = 9.2⁄2 = 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

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

Explanation

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

Q 10 - The salary of all the workers in a workshop 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 workshop is?

A - 21

B - 20

C - 22

D - 23

```Let the number of workers be z. Then,