Average- Aptitude Questions and Answers

View in English View in Hindi

What is the range of the data given below- 20, 35, 70, 65, 45, 95, 15, 80

A)
15

B)
80

C)
45

D)
95


Correct Answer :

80


Explanation :

Ordering the data from least to greatest, we get:
15, 20, 35, 45, 65, 70, 80, 95

highest - lowest = 95 - 15 = 80
The range is 80

What is the Arithmetic Mean of first 100 natural numbers?

A)
50

B)
50.5

C)
51

D)
55


Correct Answer :

50.5


Explanation :

Mean=(Total Sum of all the Values)/(No of Values)

The Sum of first ’n' natural numbers is given by,Sum=n*(n+1)/2
then, Mean=[n*(n+1)/2] / n
=n*(n+1) / 2*n

So,the mean of first 100 natural numbers, Mean=100*101 / 2*100
=101/2
=50.5

Find the mean, median, mode, and range for the following list of values ?
13, 18, 13, 14, 13, 16, 14, 21, 13

A)
15, 14, 13 and 8

B)
15, 14, 14 and 13

C)
13, 13, 13 and 13

D)
15, 14, 13 and 15


Correct Answer :

15, 14, 13 and 8


Explanation :

Mean :To find the mean, add all the numbers together then divide by the number of numbers.
Mean = (13 + 18 + 13 + 14 + 13 + 16 + 14 + 21 + 13) / 9 = 15

Median:To find the median, order the numbers and see which one is in the middle of the list.
Reordered = 13, 13, 13, 13, 14, 14, 16, 18, 21 - the middle term is 14 ie Median=14

Mode:To find the mode, order the numbers lowest to highest and see which number appears the most often.
13 is the number which appears the most often

Range:To find the range, subtract the lowest number from the biggest number.
Reordered = 13, 13, 13, 13, 14, 14, 16, 18, 21
Range = ( 21- 13 ) = 8

The average of the first 10 prime numbers?

A)
10.1

B)
10

C)
12.9

D)
13


Correct Answer :

12.9


Explanation :

First 10 prime numbers are 2,3,5,7,11,13,17,19,23,29

Average =(2+3+5+7+11+13+17+19+23+29)/10
=129/10
=12.9

Two years ago, the average age of a family of 8 members was 18 years. The average age of the family after the birth of a child is the same today. How old is the child?

A)
2 years

B)
1*(1/2) years

C)
1 year

D)
2*(1/2) years


Correct Answer :

2 years


Explanation :

As given, after birth of child average age is same ie 18 years.
hence age of child is 2 years

The average of 9 full numbers is 11 but after calculation, it was seen that while computing by the mistake the 23 was written to 32. What will be the new average after making appropriate amendment?

A)
10

B)
9

C)
10.1

D)
9.5


Correct Answer :

10


Explanation :

The average of 9 numbers = 11
Therefore, the total is = 9*11 =99
But by mistake the 23 was written 32
So, new avarage =(99+23-32)/9
=90/9
=10

The average of first three numbers out of four numbers are 18 and the average of the last three numbers is 16. If the last number is 19, then the first number is?

A)
19

B)
18

C)
20

D)
25


Correct Answer :

25


Explanation :

Let the numbers are A, B ,C and D, then as given
A+B+C=18*3=54
B+C+D=16*3=48
After resolving the above equations -
A-D=6
the last number is 19 ie D=19
So, A=6+19 =25

The average of seven consecutive numbers is 20, then the largest number in those numbers is?

A)
24

B)
23

C)
22

D)
20


Correct Answer :

23


Explanation :

Let the numbers are X to ..(X+6).
As given,
X+(X+1)+(X+2)+(X+3)+(X+4)+(X+5)+(X+6)=20*7
7*X+21=140
7*X=119
X=17
Hence, the largest number is=(X+6) =17+6 =23

A man bought 13 items worth Rs 70, 15 items worth Rs 60 and 12 items worth 65 rupees. Average value per item is?

A)
60.25

B)
64.75

C)
65.75

D)
63.25


Correct Answer :

64.75


Explanation :

Average value=(13*70)+(15*60)+(12*65) / (13+15+12)
=2590/40
=64.75

If the average of 20-digit X1, X2, ... X20 is Y, then what is the average of X1-101, X2-101, X3-101 ..... X20-101?

A)
Y-20

B)
Y-101

C)
20Y

D)
101Y


Correct Answer :

Y-101


Explanation :

Average = (X1+ X2+X3 +... +X20)/20 - (101*20)/20
=Y-101

The average of 27 numbers is 60. If instead of 28 one number has changed to 82, what will be the average?

A)
56

B)
58

C)
62

D)
64


Correct Answer :

62


Explanation :

New average = (27*60)- 28 + 82 / 27
=1620-28+82 / 27
=1674/27
=62

A factory buys 8 machines.3 Machine A, 2 Machine B and rest Machine C. Prices of the machines are 100000, 80000 and 45000 respectively.Calculate the average cost of these machines?

A)

74375


B)

75000


C)

75625


D)

72875



Correct Answer :

74375


Explanation :

Average cost of all the machines =(3*100000 + 2*80000 + 3*45000) / 8
= 595000/8
= 74375

The mean of 5 numbers is 15. If one more number is included, the mean of the 6 numbers becomes 17. What is the included number?

A)
24

B)
25

C)
26

D)
27


Correct Answer :

27


Explanation :

Sum of these 5 numbers = Mean*Total Number = 15*5 = 75
Let the number included is x.
As given
75+x / 6 = 17
75+x = 17*6
x = 102-75
x = 27

The mean marks obtained by 300 students in a subject are 60. The mean of top 100 students was found to be 80 and the mean of last 100 students was found to be 50. The mean marks of the remaining 100 students are?

A)
70

B)
65

C)
60

D)
50


Correct Answer :

50


Explanation :

Total marks of remaining(middle 100) students = 300*60 - 100*80 - 100*50
= 18000 - 8000 - 5000
= 18000 - 13000 = 5000

Hence, Mean marks of remaining 100 students = 5000/100 = 50

In an asymmetrical distribution, of the mean and median of the distribution are 270 and 220 respectively, then the mode of the data is?

A)
120

B)
220

C)
380

D)
370


Correct Answer :

120


Explanation :

Mode = 3 Median - 2 Mean
= 3*220 - 2*270
= 660 - 540
= 120

Let a, b, c, d, e, f, g be consecutive even numbers and j, k, l, m, n be consecutive odd numbers. What is the average of all the numbers?

A)
3(a + n) /2

B)
(5l + 7d )/4

C)
(a + b + m + n)/4

D)
(7d + 5l) /12


Correct Answer :

(7d + 5l) /12


Explanation :

Let a = x (even)
b = x + 2, c = x + 4, d = x + 6
e = x + 8, f = x + 10, g = x + 12
a + b + c + d + e + f + g = 7x + 42
= 7(x + 6) = 7d
And j = y (odd), k = y + 2,
l = y + 4, m = y + 6, n = y + 8
j + k + l + m+ n = 5y + 20
= 5( y + 4) = 5l

Average of all the numbers = (7d + 5l) /12

Latest Updates

Physics

Atmospheric pressure at sea level equals ?

General Knowledge of India

Which of the following dance forms was introduced by the great Vaishnava saint and reformer Mahapurusha Sankaradeva ?

Which of the following is the only classical dance of india having links with Muslim culture and represents a unique synthesis of Hindu and Muslim genius in art ?

Time and Distance

Starting from the same point at the same time, Ruhan and Yuvan had to reach the same destination. While Ruhan drove at 45 km/hr, Yuvan was slower by 5 km/hr. If Yuvan arrived at the destination an hour after Ruhan did, the distance covered by each, in Kilometres, was ?

Simple Interest

A sum of money was invested at a certain rate of simple interest for 4 years. Had the sum been invested at a rate 3% higher than the actual rate, the interest earned would have been 720 Rs more. Find the sum initially invested?

Ratio and Proportion

A bag contains red, blue and black balls. The ratio of red to blue balls is 3 : 5. The ratio of black to red balls is 3 : 4. What is the ratio of blue to black balls?

Profit and Loss

Selling a pack of incense sticks for 136 Rs resulted in a loss of 15%. To make a profit of 10%, the selling price should be ?

Percentage

23% of a bucket full of diluted milk was water. If the quantity of pure milk in the bucket was 15.4 liter, then the capacity of the bucket was ?

Average

The average of the marks obtained by three girls in a test was twice the average of the marks obtained by eight boys in that test. If the total marks obtained by all these examinees was 168, find the average marks each of the girls obtained ?

Pipes and Cistern

44 pipes can fill a large water tank in 27 hours. How many hours it take for 66 pipes to fill four such tanks ?

HCF and LCM

A natural number, when divided by 3, 4, 5, 6, and 7 respectively, leaves corresponding remainder of 2, 3, 4, 5 and 6. What is the smallest of all such numbers fulfilling the above condition ?

Coding-Decoding

If in a certain code language, PRINT is written as 34825 and TRUE is written as 5479. Then, how will TENURE be written in that language?

Order Sequence

Arrange the given words from smallest to biggest-
1.Jug
2.Mug
3.Bucket
4.Drum
5.Cup

Statement and Conclusion

Statements
All socks are shoes
Some shoes are black

Conclusions
I. Some shoes are socks.
II. No scoks is black

Numbers

The difference between the place value of 4 and 2 in the number 833749502 is ?

Analogy

GIKM : HJLN :: PRTV : .........?

Order Sequence

In a row of girls, Nanda is eighth from the left and Chanda is nineteenth from right. When Nanda and Chanda interchange their positions, Chanda becomes twnty-third form right. How many girls are there in the row?

Analogy

Summer: Day :: Winter : ........?