Mathematics
Average / Arithmetic Mean
Two numbers are equally distant from 31; the smaller is 25. What is the larger number if their average is 31?
A. 37
B. 41
C. 35
D. 39
Correct Answer: A
The numbers are symmetric about 31; larger = 31+6=37.
Mathematics
Average / Arithmetic Mean
Two numbers are equally distant from 28; the smaller is 23. What is the larger number if their average is 28?
A. 35
B. 37
C. 31
D. 33
Correct Answer: D
The numbers are symmetric about 28; larger = 28+5=33.
Mathematics
Average / Arithmetic Mean
Two numbers are equally distant from 25; the smaller is 21. What is the larger number if their average is 25?
A. 33
B. 29
C. 31
D. 27
Correct Answer: B
The numbers are symmetric about 25; larger = 25+4=29.
Mathematics
Average / Arithmetic Mean
A collection has mean 27. After one value 44 is added, the mean becomes 28. How many values were originally present?
A. 15
B. 16
C. 17
D. 18
Correct Answer: B
Let count be n: 27n+44=28(n+1). Solving gives n=16.
Mathematics
Average / Arithmetic Mean
A collection has mean 26. After one value 42 is added, the mean becomes 27. How many values were originally present?
A. 15
B. 14
C. 17
D. 16
Correct Answer: A
Let count be n: 26n+42=27(n+1). Solving gives n=15.
Mathematics
Average / Arithmetic Mean
A collection has mean 25. After one value 40 is added, the mean becomes 26. How many values were originally present?
A. 15
B. 14
C. 16
D. 13
Correct Answer: B
Let count be n: 25n+40=26(n+1). Solving gives n=14.
Mathematics
Average / Arithmetic Mean
A collection has mean 24. After one value 38 is added, the mean becomes 25. How many values were originally present?
A. 15
B. 14
C. 13
D. 12
Correct Answer: C
Let count be n: 24n+38=25(n+1). Solving gives n=13.
Mathematics
Average / Arithmetic Mean
A collection has mean 23. After one value 36 is added, the mean becomes 24. How many values were originally present?
A. 13
B. 14
C. 12
D. 11
Correct Answer: C
Let count be n: 23n+36=24(n+1). Solving gives n=12.
Mathematics
Average / Arithmetic Mean
A collection has mean 22. After one value 34 is added, the mean becomes 23. How many values were originally present?
A. 13
B. 11
C. 12
D. 10
Correct Answer: B
Let count be n: 22n+34=23(n+1). Solving gives n=11.
Mathematics
Average / Arithmetic Mean
A collection has mean 21. After one value 32 is added, the mean becomes 22. How many values were originally present?
A. 12
B. 10
C. 9
D. 11
Correct Answer: B
Let count be n: 21n+32=22(n+1). Solving gives n=10.
Mathematics
Average / Arithmetic Mean
A collection has mean 20. After one value 30 is added, the mean becomes 21. How many values were originally present?
A. 9
B. 10
C. 8
D. 11
Correct Answer: A
Let count be n: 20n+30=21(n+1). Solving gives n=9.
Mathematics
Average / Arithmetic Mean
A collection has mean 19. After one value 28 is added, the mean becomes 20. How many values were originally present?
A. 8
B. 10
C. 9
D. 7
Correct Answer: A
Let count be n: 19n+28=20(n+1). Solving gives n=8.
Mathematics
Average / Arithmetic Mean
A collection has mean 18. After one value 26 is added, the mean becomes 19. How many values were originally present?
A. 7
B. 8
C. 9
D. 6
Correct Answer: A
Let count be n: 18n+26=19(n+1). Solving gives n=7.
Mathematics
Average / Arithmetic Mean
The average of x+17, x+34, and x+51 is 38. What is x?
A. 8
B. 2
C. 6
D. 4
Correct Answer: D
The mean is x+34; hence x=38-34=4.
Mathematics
Average / Arithmetic Mean
The average of x+16, x+32, and x+48 is 36. What is x?
A. 2
B. 4
C. 6
D. 8
Correct Answer: B
The mean is x+32; hence x=36-32=4.
Mathematics
Average / Arithmetic Mean
The average of x+15, x+30, and x+45 is 34. What is x?
A. 2
B. 4
C. 8
D. 6
Correct Answer: B
The mean is x+30; hence x=34-30=4.
Mathematics
Average / Arithmetic Mean
The average of x+14, x+28, and x+42 is 32. What is x?
A. 2
B. 8
C. 6
D. 4
Correct Answer: D
The mean is x+28; hence x=32-28=4.
Mathematics
Average / Arithmetic Mean
The average of x+13, x+26, and x+39 is 30. What is x?
A. 6
B. 8
C. 2
D. 4
Correct Answer: D
The mean is x+26; hence x=30-26=4.
Mathematics
Average / Arithmetic Mean
The average of x+12, x+24, and x+36 is 28. What is x?
A. 6
B. 4
C. 8
D. 2
Correct Answer: B
The mean is x+24; hence x=28-24=4.
Mathematics
Average / Arithmetic Mean
The average of x+11, x+22, and x+33 is 26. What is x?
A. 2
B. 6
C. 4
D. 8
Correct Answer: C
The mean is x+22; hence x=26-22=4.