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

Or

2 years back total age of 8 members = 18 * 8 = 144 years
Total present age of 8 members = 144 + 2*8 = 160 years
Now, a child born, average age reamin same, that is Average age of 9 people = 18
Toatl age of 9 people = 18 * 9 = 162 years.
Age of child = 162 - 160 = 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

Pipes and Cistern

Three taps A,B and C can fill a tank in 12, 15 and 20 hours respectively. If A is open all the time and B and C are open for one hour each alternatively, the tank will be full in?

Two pipes A and B can fill a tank in 6 hours and 4 hours respectively. If they are opened on alternate hours and if pipe A s opened first, in how many hours, the tank shall be full?

A large tanker can be filled by two pipes A and B in 60 min and 40 min respectively. How many minutes will it take to fill the tanker from empty state if B is used for first half of the time, and A and B fill it together for the other half?

A tank is filled by 3 pipes with uniform flow. The first two pipes operating simultaneously fill the tank in the same time during which the tank is filled by the third pipe alone. The 2nd pipe fills the tank 5 hours faster than first pipe and 4 hours slower than third pipe. The time required by first pipe is?

Two pipes A and B together can fill a cistern in 4 hours. Had they been opened separately, then B would have taken 6 hours more than A to fill the cistern. How much time will be taken by A to fill the cistern separately?

Two pipes A and B can fill a tank in 24 min and 32 min respectively. If both the pipes are opened simultaneously, after how much time B should be closed so that the tank is full in 18 min?

Two pipes A and B can fill a tank in 36 min and 45 min respectively. A water pipe C can empty the tank in 30 min. First A and B are opened. after 7 min, C is also opened. In how much time, the tank is full?

Two pipes can fill a cistern in 14 hours and 16 hours respectively. The pipes are opened simultaneously and it is found that due to leakage in the bottom it took 32 min more to fill the cistern. When the cistern is full, in what time will the leak empty it?

Bucket P has thrice the capacity as Bucket Q. It takes 60 turns for Bucket P to fill the empty drum. How many turns it will take for both the buckets P and Q, having each turn together to fill the empty drum?

Probability

In a class , 30 % of the students offered English, 20 % offered Hindi and 10 % offered Both.If a student is offered at random, what is the probability that he has offered English or Hindi?

In a lottery ,there are 10 prizes and 25 blanks.A lottery is drawn at random. what is the probability of getting a prize ?

Two dice are thrown simultaneously .what is the probability of getting two numbers whose product is even?

Two diced are tossed the probability that the total score is a prime number?

Two cards are drawn at random from a pack of 52 cards What is the probability that either both are black or both are queens?

Two dice are thrown together .What is the probability that the sum of the number on the two faces is divisible by 4 or 6?

A bag contains 6 white and 4 black balls .Two balls are drawn at random .Find the probability that they are of the same colour?

In a simultaneous throw of a pair of dice,find the probability of getting a total more than 7?

An unbiased die is tossed.Find the probability of getting a multiple of 3?

Latest Job Notifications

Banking Jobs

बैंकिंग कार्मिक चयन संस्थान Institute of Banking Personnel Selection(IBPS) - 7855 पद - 29/07/2022 अंतिम तिथि

SSC Recruitment

कर्मचारी चयन आयोग (एसएससी) Staff Selection Commission (SSC) - 1411 पद - 29/07/2022 अंतिम तिथि

Jobs in Rajasthan

राजस्थान अधीनस्थ और मंत्रिस्तरीय सेवा चयन बोर्ड Rajasthan Subordinate and Ministerial Services Selection Board (RSMSSB) - 5546 पद - 22-Jul-2022 अंतिम तिथि

Railway Recruitment

उत्तर मध्य रेलवे भर्ती प्रकोष्ठ Railway Recruitment Cell(NCR) - 1659 पद - 01/08/2022 अंतिम तिथि

Jobs in West Bengal

इंडियन पोस्ट सर्विस Indian Post Service - 2357 पद - 19/08/2021 अंतिम तिथि - पश्चिम बंगाल पोस्टल सर्कल

Banking Jobs

भारतीय स्टेट बैंक State Bank of India(SBI) - 6100 पद - 26/07/2021 अंतिम तिथि - CRPD/APPR/2021-22/10

SSC Recruitment

कर्मचारी चयन आयोग Staff Selection Commission(SSC) - 25271 पद - 31/08/2021 अंतिम तिथि

Jobs in Madhya Pradesh

राष्ट्रीय स्वास्थ्य मिशन मध्य प्रदेश National Health Mission MP(NRHM) - 5215 पद - 22/06/2021 अंतिम तिथि

Jobs in Punjab

पंजाब स्टेट पावर कॉर्पोरेशन लिमिटेड Punjab State Power Corporation Limited (PSPCL) - 2632 पद - 20/06/2021 अंतिम तिथि

Jobs in Chhattisgarh

स्वास्थ्य सेवा निदेशालय, छत्तीसगढ़ Department of Health & Family Welfare, Chhattisgarh - 267 पद - 26/06/2021 अंतिम तिथि