21. The average of 8 numbers is 50. What is the sum of these 8 numbers?
a) 400
b) 450
c) 480
d) 500
[show_answer]The correct answer is: A [/show_answer]
22. The average of 5 numbers is 20. If four numbers are 10, 15, 25, and 30, what is the fifth number?
a) 10
b) 20
c) 25
d) 30
[show_answer]The correct answer is: C [/show_answer]
23. The average of three numbers is 20. If two numbers are 15 and 25, what is the third number?
a) 20
b) 30
c) 40
d) 45
[show_answer]The correct answer is: B [/show_answer]
24. The average of 6 numbers is 32. If the first 5 numbers are 28, 35, 30, 40, and 25, what is the sixth number?
a) 31
b) 33
c) 34
d) 36
[show_answer]The correct answer is: C [/show_answer]
25. The average of 12 numbers is 72. If the sum of the first 11 numbers is 792, what is the 12th number?
a) 72
b) 80
c) 90
d) 100
[show_answer]The correct answer is: B [/show_answer]
