RRB Group D Central Tendencies – Mean
In the context of RRB (Railway Recruitment Board) Group D exams or any statistical analysis, “central tendencies” typically refer to measures that indicate the center or average of a data set. The mean is one such measure of central tendency.
1.What is the mean of the following set of numbers: 5, 8, 12, 15, 20?
a) 10
b) 12
c) 15
d) 17.5
Answer: d) 17.5
2.If the mean of a dataset is 25 and there are 5 data points, what is the sum of all the values in the dataset?
a) 100
b) 125
c) 150
d) 175
Answer: c) 150
3.The mean of three numbers is 10. If two of the numbers are 8 and 12, what is the third number?
a) 6
b) 10
c) 14
d) 18
Answer: a) 6
4.If the mean of a set of numbers is 30 and one of the numbers is 45, what is the mean if the 45 is removed?
a) 25
b) 30
c) 35
d) 40
Answer: a) 25
5.In a class of 20 students, the mean score in a test is 75. If one student’s score is incorrectly recorded as 50 instead of 70, what is the correct mean?
a) 72.5
b) 73
c) 73.5
d) 74
Answer: c) 73.5
6.The mean of a set of 8 numbers is 12. If one number is added to the set, making it 9 numbers in total, and the new mean becomes 15, what is the value of the added number?
a) 12
b) 15
c) 18
d) 21
Answer: c) 18
7.The mean of five numbers is 24. If one number is removed from the set, and the new mean becomes 22, what is the value of the removed number?
a) 18
b) 20
c) 22
d) 24
Answer: b) 20
8.If the mean of a dataset is 50 and the dataset has 6 numbers, what is the sum of all the numbers in the dataset?
a) 250
b) 300
c) 350
d) 400
Answer: b) 300
9.In a company, the salaries of five employees are $40,000, $50,000, $60,000, $70,000, and $80,000. What is the mean salary?
a) $55,000
b) $60,000
c) $65,000
d) $70,000
Answer: b) $60,000
10.If the mean of a set of 7 numbers is 18, and one number in the set is 25, what is the mean if 25 is replaced with 15?
a) 15
b) 16
c) 17
d) 18
Answer: c) 17
11.The mean of a set of 10 numbers is 30. If each number in the set is multiplied by 2, what is the new mean?
a) 30
b) 40
c) 50
d) 60
Answer: c) 50
12.If the mean of a dataset is 22 and one of the numbers is 18, what is the mean if another number, 30, is added to the dataset?
a) 20
b) 22
c) 24
d) 26
Answer: c) 24
13.In a class, the mean score in a math test is 75. If a student who scored 90 joins the class, what is the new mean?
a) 75
b) 80
c) 85
d) 90
Answer: b) 80
14.The mean of three numbers is 15. If the largest number in the set is 25, what is the mean of the other two numbers?
a) 10
b) 15
c) 20
d) 25
Answer: a) 10
15.If the mean of a set of numbers is 40 and the numbers are 30, 40, and 50, what is the mean if another number, 60, is added to the set?
a) 40
b) 45
c) 50
d) 55
Answer: c) 50
16.The mean of four numbers is 18. If one number is subtracted from the set, making it three numbers in total, and the new mean becomes 15, what is the value of the subtracted number?
a) 3
b) 5
c) 7
d) 9
Answer: b) 5
17.If the mean of a set of numbers is 16 and the numbers are 10, 12, 16, and 18, what is the mean if each number is multiplied by 3?
a) 16
b) 24
c) 32
d) 48
Answer: c) 32
18.The mean of a dataset is 40. If each value in the dataset is increased by 5, what is the new mean?
a) 35
b) 40
c) 45
d) 50
Answer: b) 40
19.In a group of friends, the ages are 20, 22, 24, 26, and 28. What is the mean age?
a) 22
b) 24
c) 26
d) 28
Answer: b) 24
20.If the mean of a set of numbers is 60 and the numbers are 50, 60, 70, and 80, what is the mean if the highest number, 80, is replaced with 90?
a) 60
b) 65
c) 70
d) 75
Answer: c) 70
21.If the mean of a set of 6 numbers is 25, and one of the numbers is 15, what is the mean if 15 is replaced with 35?
a) 25
b) 30
c) 35
d) 40
Answer: b) 30
22.The mean of a set of 5 numbers is 18. If each number in the set is divided by 2, what is the new mean?
a) 9
b) 12
c) 15
d) 18
Answer: a) 9
23.In a school, the average height of 8 students is 150 cm. If a new student, whose height is 160 cm, joins the school, what is the new average height?
a) 148 cm
b) 150 cm
c) 152 cm
d) 154 cm
Answer: c) 152 cm
24.The mean of four consecutive even numbers is 14. What is the largest number in the set?
a) 12
b) 14
c) 16
d) 18
Answer: c) 16
25.If the mean of a set of 7 numbers is 40 and the numbers are 30, 40, 50, and 60, what is the mean if one number, 70, is added to the set?
a) 45
b) 50
c) 55
d) 60
Answer: c) 55
RRB Group D Simple and Compound Interest
1.If the principal amount is $1000, the rate of interest is 5%, and the time period is 2 years, what is the simple interest?
a) $50
b) $100
c) $150
d) $200
Answer:b) $100
2.Find the compound interest on $1200 at an annual rate of 8% for 2 years, compounded annually.
a) $153.60
b) $156.80
c) $160.16
d) $164.64
Answer:c) $160.16
3.If the principal amount is $5000, the rate of interest is 4%, and the time period is 3 years, what is the compound interest compounded annually?
a) $631.20
b) $649.28
c) $664.32
d) $672.32
Answer:b) $649.28
4.A sum of $8000 is invested at a compound interest rate of 6% per annum for 2 years. What will be the amount after 2 years?
a) $8972
b) $9156
c) $9248
d) $9416
Answer:c) $9248
5.If the simple interest on a certain sum of money for 2 years at 10% per annum is $500, what is the principal amount?
a) $2000
b) $2500
c) $3000
d) $3500
Answer:c) $3000
6.If the compound interest on a certain amount for 2 years at 12% per annum is $144, what is the principal amount?
a) $500
b) $600
c) $800
d) $1000
Answer:c) $800
7.A sum of money becomes four times itself in 3 years at a certain rate of interest. What is the rate of interest per annum?
a) 25%
b) 30%
c) 35%
d) 40%
Answer:a) 25%
8.The difference between the simple interest and compound interest on a certain sum of money for 2 years at 8% per annum is $32. What is the principal amount?
a) $1000
b) $1200
c) $1500
d) $2000
Answer:d) $2000
9.If the principal amount is $3000, the time period is 3 years, and the compound interest is $927.09, what is the rate of interest per annum?
a) 7%
b) 9%
c) 11%
d) 13%
Answer:a) 7%
10.A certain amount of money triples itself in 5 years at a certain rate of simple interest. What is the rate of interest per annum?
a) 15%
b) 20%
c) 25%
d) 30%
Answer:a) 15%
11.The compound interest on a certain sum of money for 2 years at 10% per annum is $441. What is the principal amount?
a) $1600
b) $1700
c) $1800
d) $1900
Answer:c) $1800
12.If the simple interest on a sum of money for 4 years at 6% per annum is $240, what is the principal amount?
a) $800
b) $1000
c) $1200
d) $1500
Answer:b) $1000
13.A principal amount of $5000 is invested at a simple interest rate of 8% per annum. What is the interest earned after 3 years?
a) $960
b) $1200
c) $1440
d) $1800
Answer:a) $960
14.If the compound interest on a sum of money for 3 years at 15% per annum is $732.75, what is the principal amount?
a) $2000
b) $2500
c) $3000
d) $3500
Answer:c) $3000
15.The compound interest on a certain amount for 2 years at 8% per annum is $256. What will be the amount after 2 years?
a) $3200
b) $3328
c) $3456
d) $3584
Answer:b) $3328
16.The simple interest on a certain sum of money for 5 years at 6% per annum is $300. What is the principal amount?
a) $4000
b) $4500
c) $5000
d) $5500
Answer:c) $5000
17.If the compound interest on a certain amount for 2 years at 12% per annum is $576, what is the principal amount?
a) $2000
b) $2400
c) $2800
d) $3200
Answer:b) $2400
18.The compound interest on a sum of money for 3 years at 10% per annum is $331. What is the principal amount?
a) $800
b) $900
c) $1000
d) $1100
Answer:c) $1000
19.A certain amount of money invested at 5% per annum yields a simple interest of $125 in 4 years. What is the principal amount?
a) $500
b) $600
c) $700
d) $800
Answer:d) $800
20.If the principal amount is $7000, the rate of interest is 8%, and the compound interest is $1232, what is the time period?
a) 2 years
b) 3 years
c) 4 years
d) 5 years
Answer:b) 3 years
21.If the principal amount is $4000, the rate of interest is 9%, and the time period is 2 years, what is the compound interest compounded annually?
a) $648
b) $729
c) $810
d) $891
Answer:b) $729
22.The compound interest on a certain sum of money for 4 years at 15% per annum is $1225. What is the principal amount?
a) $2500
b) $3000
c) $3500
d) $4000
Answer:b) $3000
23.A sum of $6000 is invested at a compound interest rate of 5% per annum for 3 years. What will be the compound interest?
a) $925
b) $950
c) $975
d) $1000
Answer:b) $950
24.If the simple interest on a certain sum of money for 4 years at 8% per annum is $640, what is the principal amount?
a) $1600
b) $1800
c) $2000
d) $2200
Answer:c) $2000
25.The difference between the simple interest and compound interest on a certain sum of money for 2 years at 12% per annum is $36. What is the principal amount?
a) $150
b) $200
c) $250
d) $300
Answer:a) $150
26.The compound interest on a certain sum of money for 2 years at 15% per annum is $525. What is the principal amount?
a) $1200
b) $1400
c) $1600
d) $1800
Answer:c) $1600
27.If the principal amount is $3000, the rate of interest is 6%, and the time period is 3 years, what is the simple interest?
a) $540
b) $540
c) $630
d) $720
Answer:b) $540
28.If the principal amount is $5000, the rate of interest is 8%, and the compound interest is $820, what is the time period?
a) 2 years
b) 3 years
c) 4 years
d) 5 years
Answer:c) 4 years
29.A sum of $5000 is invested at a simple interest rate of 4% per annum. What is the interest earned after 2 years?
a) $320
b) $400
c) $480
d) $560
Answer:c) $480
RRB Group D Order of Magnitude,Ratio,Proportion and Variation MCQ