CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
The average of 6 numbers is 36. If 5 of them are 35, 35, 35, 39, 35, find the missing number.
A. 40
B. 37
C. 34
D. 43
Correct Answer: B
Total = 6×36=216; missing = 216−179=37.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
The average of 5 numbers is 34. If 4 of them are 34, 34, 34, 34, find the missing number.
A. 37
B. 31
C. 40
D. 34
Correct Answer: D
Total = 5×34=170; missing = 170−136=34.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
The average of 8 numbers is 32. If 7 of them are 32, 32, 33, 32, 32, 32, 32, find the missing number.
A. 34
B. 31
C. 28
D. 37
Correct Answer: B
Total = 8×32=256; missing = 256−225=31.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
The average of 7 numbers is 30. If 6 of them are 30, 30, 30, 30, 32, 30, find the missing number.
A. 34
B. 25
C. 31
D. 28
Correct Answer: D
Total = 7×30=210; missing = 210−182=28.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
The average of 6 numbers is 28. If 5 of them are 28, 31, 28, 28, 28, find the missing number.
A. 22
B. 31
C. 28
D. 25
Correct Answer: D
Total = 6×28=168; missing = 168−143=25.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
The average of 5 numbers is 26. If 4 of them are 27, 27, 27, 27, find the missing number.
A. 22
B. 28
C. 19
D. 25
Correct Answer: A
Total = 5×26=130; missing = 130−108=22.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
The average of 8 numbers is 24. If 7 of them are 24, 24, 24, 24, 24, 24, 29, find the missing number.
A. 22
B. 25
C. 16
D. 19
Correct Answer: D
Total = 8×24=192; missing = 192−173=19.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
The average of 7 numbers is 22. If 6 of them are 23, 23, 23, 23, 23, 23, find the missing number.
A. 13
B. 19
C. 16
D. 22
Correct Answer: C
Total = 7×22=154; missing = 154−138=16.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
The average of 6 numbers is 20. If 5 of them are 23, 21, 21, 21, 21, find the missing number.
A. 10
B. 13
C. 19
D. 16
Correct Answer: B
Total = 6×20=120; missing = 120−107=13.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
The average of 5 numbers is 18. If 4 of them are 20, 20, 20, 20, find the missing number.
A. 7
B. 16
C. 13
D. 10
Correct Answer: D
Total = 5×18=90; missing = 90−80=10.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
If the average of x and y is 25, then x + y equals:
A. 50
B. 625
C. 25
D. 12.5
Correct Answer: A
(x+y)/2=25, so x+y=50.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
Which statement is always true for an arithmetic mean?
A. Mean is always one observation
B. Sum of deviations from the mean is zero
C. Mean is always the largest value
D. Mean cannot be decimal
Correct Answer: B
Deviations from the arithmetic mean sum to zero.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
The average of 5 equal numbers, each equal to 27, is:
A. 5
B. 22
C. 135
D. 27
Correct Answer: D
Equal observations have the same value as their mean.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
If every observation is multiplied by 4, what happens to the average?
A. It remains unchanged
B. It is divided by 4
C. It is multiplied by 4
D. It increases by 4 only
Correct Answer: C
Multiplying every value by 4 multiplies the mean by 4.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
Which formula gives the arithmetic mean of n observations?
A. Largest value − smallest value
B. n ÷ Sum of observations
C. Sum of observations × n
D. Sum of observations ÷ n
Correct Answer: D
Arithmetic mean is total ÷ count.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
What is the average of the first 17 natural numbers?
A. 9
B. 13
C. 7
D. 11
Correct Answer: A
Average of 1 to n = (n+1)/2 = 9.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
What is the average of the first 15 natural numbers?
A. 6
B. 8
C. 10
D. 12
Correct Answer: B
Average of 1 to n = (n+1)/2 = 8.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
What is the average of the first 13 natural numbers?
A. 11
B. 5
C. 7
D. 9
Correct Answer: C
Average of 1 to n = (n+1)/2 = 7.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
What is the average of the first 11 natural numbers?
A. 10
B. 6
C. 8
D. 4
Correct Answer: B
Average of 1 to n = (n+1)/2 = 6.
CSS - PMS - CCE - PCS - Mathematics
Average / Arithmetic Mean
What is the average of the first 9 natural numbers?
A. 5
B. 7
C. 9
D. 3
Correct Answer: A
Average of 1 to n = (n+1)/2 = 5.