Mathematics
Average / Arithmetic Mean
One batch averages 26 and another averages 58. Their combined mean is 40.22. In what ratio are the batch sizes (first:second)?
A. 5:5
B. 4:5
C. 6:4
D. 5:4
Correct Answer: D
By alligation, first:second = (58−40.22):(40.22−26) = 5:4.
Mathematics
Average / Arithmetic Mean
One batch averages 25 and another averages 56. Their combined mean is 38.29. In what ratio are the batch sizes (first:second)?
A. 5:3
B. 4:3
C. 3:4
D. 4:4
Correct Answer: B
By alligation, first:second = (56−38.29):(38.29−25) = 4:3.
Mathematics
Average / Arithmetic Mean
One batch averages 24 and another averages 54. Their combined mean is 36. In what ratio are the batch sizes (first:second)?
A. 2:3
B. 3:3
C. 3:2
D. 4:2
Correct Answer: C
By alligation, first:second = (54−36):(36−24) = 3:2.
Mathematics
Average / Arithmetic Mean
A group has overall mean 49.04. One section has 17 members averaging 39; the other section averages 68. How many members are in the second section?
A. 9
B. 11
C. 8
D. 10
Correct Answer: A
Use the combined-mean equation and solve for the second count: 9.
Mathematics
Average / Arithmetic Mean
A group has overall mean 47.33. One section has 16 members averaging 38; the other section averages 66. How many members are in the second section?
A. 10
B. 7
C. 9
D. 8
Correct Answer: D
Use the combined-mean equation and solve for the second count: 8.
Mathematics
Average / Arithmetic Mean
A group has overall mean 45.59. One section has 15 members averaging 37; the other section averages 64. How many members are in the second section?
A. 6
B. 8
C. 9
D. 7
Correct Answer: D
Use the combined-mean equation and solve for the second count: 7.
Mathematics
Average / Arithmetic Mean
A group has overall mean 43.8. One section has 14 members averaging 36; the other section averages 62. How many members are in the second section?
A. 6
B. 5
C. 7
D. 8
Correct Answer: A
Use the combined-mean equation and solve for the second count: 6.
Mathematics
Average / Arithmetic Mean
A group has overall mean 41.94. One section has 13 members averaging 35; the other section averages 60. How many members are in the second section?
A. 6
B. 5
C. 7
D. 4
Correct Answer: B
Use the combined-mean equation and solve for the second count: 5.
Mathematics
Average / Arithmetic Mean
A group has overall mean 44.29. One section has 12 members averaging 34; the other section averages 58. How many members are in the second section?
A. 10
B. 11
C. 9
D. 8
Correct Answer: C
Use the combined-mean equation and solve for the second count: 9.
Mathematics
Average / Arithmetic Mean
A group has overall mean 42.68. One section has 11 members averaging 33; the other section averages 56. How many members are in the second section?
A. 10
B. 9
C. 8
D. 7
Correct Answer: C
Use the combined-mean equation and solve for the second count: 8.
Mathematics
Average / Arithmetic Mean
A group has overall mean 41.06. One section has 10 members averaging 32; the other section averages 54. How many members are in the second section?
A. 6
B. 9
C. 7
D. 8
Correct Answer: C
Use the combined-mean equation and solve for the second count: 7.
Mathematics
Average / Arithmetic Mean
A group has overall mean 39.4. One section has 9 members averaging 31; the other section averages 52. How many members are in the second section?
A. 7
B. 8
C. 5
D. 6
Correct Answer: D
Use the combined-mean equation and solve for the second count: 6.
Mathematics
Average / Arithmetic Mean
A group has overall mean 37.69. One section has 8 members averaging 30; the other section averages 50. How many members are in the second section?
A. 7
B. 6
C. 5
D. 4
Correct Answer: C
Use the combined-mean equation and solve for the second count: 5.
Mathematics
Average / Arithmetic Mean
In a class, 26 students have an average of 47 and another 10 students have an average of 59. What is the class average?
A. 50.33
B. 49.33
C. 51.33
D. 52.33
Correct Answer: A
Combined mean = (26×47+10×59)/36 = 50.33.
Mathematics
Average / Arithmetic Mean
In a class, 25 students have an average of 46 and another 16 students have an average of 58. What is the class average?
A. 50.68
B. 52.68
C. 51.68
D. 49.68
Correct Answer: A
Combined mean = (25×46+16×58)/41 = 50.68.
Mathematics
Average / Arithmetic Mean
In a class, 24 students have an average of 45 and another 15 students have an average of 57. What is the class average?
A. 50.62
B. 48.62
C. 49.62
D. 51.62
Correct Answer: C
Combined mean = (24×45+15×57)/39 = 49.62.
Mathematics
Average / Arithmetic Mean
In a class, 23 students have an average of 50 and another 14 students have an average of 56. What is the class average?
A. 54.27
B. 52.27
C. 53.27
D. 51.27
Correct Answer: B
Combined mean = (23×50+14×56)/37 = 52.27.
Mathematics
Average / Arithmetic Mean
In a class, 22 students have an average of 49 and another 13 students have an average of 55. What is the class average?
A. 51.23
B. 50.23
C. 53.23
D. 52.23
Correct Answer: A
Combined mean = (22×49+13×55)/35 = 51.23.
Mathematics
Average / Arithmetic Mean
In a class, 21 students have an average of 48 and another 12 students have an average of 59. What is the class average?
A. 51
B. 52
C. 54
D. 53
Correct Answer: B
Combined mean = (21×48+12×59)/33 = 52.
Mathematics
Average / Arithmetic Mean
In a class, 20 students have an average of 47 and another 11 students have an average of 58. What is the class average?
A. 50.9
B. 52.9
C. 51.9
D. 49.9
Correct Answer: A
Combined mean = (20×47+11×58)/31 = 50.9.