Average - Quantitative Aptitude (MCQ) questions

1)   The average marks obtained by 100 candidates in an examination is 50. Find how many candidates have passed in the examination, if the average marks of candidates who passed is 70 and that of failed candidates is 20.
- Published on 06 May 16

a. 90
b. 75
c. 60
d. 58
Answer  Explanation 

ANSWER: 60

Explanation:
Let the number of students who passed the examination be X
Number of students failed = (100 - X)
Total marks of students who have passed = 70X
Total marks of 100 students = 100 * 50 = 5000
Total marks of students who have failed = 20(100 – X)
20(100 – X) + 70X = 5000
2000 – 20 X + 70X = 5000
50 X = 3000
X = 60


2)   Three numbers are in the ratio 4 : 5 : 6 and their average is 30 . The largest number is:
- Published on 05 May 16

a. 28
b. 32
c. 36
d. 42
Answer  Explanation 

ANSWER: 36

Explanation:
Let the numbers be 4x, 5x and 6x. Therefore,
(4x+5x+6x)/3 = 30
15x = 90
x = 6
Largest number = 6x = 36.


3)   A grocer has a sale of Rs. 5420, Rs. 5660, Rs. 6200, Rs. 6350 and Rs. 6500 for 5 consecutive months. Find the sale he should have in the sixth month, so that he gets an average sale of Rs. 6000?
- Published on 04 May 16

a. Rs. 5870
b. Rs. 5991
c. Rs. 6020
d. Rs. 6850
Answer  Explanation 

ANSWER: Rs. 5870

Explanation:
Total sale for 5 months = Rs. (5420 + 5660 + 6200 + 6350 + 6500) = Rs. 30,130
Therefore, required sale = Rs. [(6000 * 6) – 30,130] = Rs. (36000 – 30,130) = Rs. 5870


4)   The average temperature of a city in the first four days of a month was 36°. The average for the 2nd, 3rd, 4th and 5th day was 38°. If the temperature of the 1st and 5th day were in the ratio 4 : 5, then what is the temperature on the fifth day ?
- Published on 22 Apr 16

a. 32°
b. 35°
c. 38°
d. 40°
e. None of these
Answer  Explanation 

ANSWER: 40°

Explanation:
The temperature for first 4 days = 4 * 36 = 144
The temperature for last 4 days = 4 * 38 = 152
The difference between the temperatures is (152 – 144) = 8
The ratio of temperature between first and fifth day is 4 : 5
The temperature on fifth day is 5*8 = 40


5)   Ashok secured average of 75 marks in 6 subjects. If the average of marks in 5 subjects is 74, how many marks did he secure in the 6th subject?
- Published on 19 Apr 16

a. 66
b. 74
c. 78
d. 80
e. None of these
Answer  Explanation 

ANSWER: 80

Explanation:
Number of subjects = 6
Average of marks in 6 subjects = 75
Therefore total marks in 6 subjects = 75 * 6 = 450
Now, No. of subjects = 5
Total marks in 5 subjects = 74 * 5 = 370
Therefore marks in 6th subject = 450 – 370 = 80


6)   A girl purchased “m” number of pens of type “A” at the unit price of “Rs. x” each, “n” number of pens of type “B” at the unit price of “Rs. y” each and “p” number of pens of type “C” at the unit price of “Rs. z” each. Which of the following represents the average price of all the pens taken together?
- Published on 15 Apr 16

a. (mx + ny + pz) / (m + n + p)
b. (mA + nB + pC) / (m + n + p)
c. (mA + nB + pC) / (A + B + C)
d. (mx + ny + pz) / (A +B + C)
Answer  Explanation 

ANSWER: (mx + ny + pz) / (m + n + p)

Explanation:
(mx + ny + pz) / (m + n + p)
Required Average = Total Price / Total number = (mx + ny + pz) / (m + n + p)


7)   The average runs of a cricket player of 10 innings was 20. How many runs must he make in his next innings so as to increase his average of runs by 4?
- Published on 13 Apr 16

a. 12
b. 42
c. 64
d. 76
Answer  Explanation 

ANSWER: 64

Explanation:
Average after 11 innings = 24
Required number of runs = (24 * 11) – (20 * 10)
= 264 – 200 = 64


8)   Find the average of all the numbers between 11 and 36 which are divisible by 5.
- Published on 12 Apr 16

a. 15
b. 20
c. 25
d. 30
Answer  Explanation 

ANSWER: 25

Explanation:
Average = (15 + 20 + 25 + 30 + 35) / 5 = 125/5 = 25


9)   If x = 2, then what is the value of 8x √x3 – x2
- Published on 12 Apr 16

a. 32
b. 48
c. 16√2
d. 90
Answer  Explanation 

ANSWER: 32

Explanation:
Given: x = 2
8 * 2 √23 – 22
16√8-4
16√4
16 * 2 = 32


10)   The average of five consecutive odd numbers is 51. What is the difference between the highest and lowest number?
- Published on 07 Apr 16

a. 3
b. 7
c. 8
d. 11
e. None of these
Answer  Explanation 

ANSWER: 8

Explanation:
Let the numbers be x, x + 2, x + 4, x + 6 and x + 8.
Then, [x + (x + 2) + (x + 4) + (x + 6) + (x + 8)] / 5 = 51
5x + 20 = 255
x = 47
So, required difference = (47 + 8) – 47 = 8


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