21. The average of 8 numbers is 50. What is the sum of these 8 numbers?
a) 400
b) 450
c) 480
d) 500
The correct answer is: A
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
The correct answer is: C
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
The correct answer is: B
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
The correct answer is: C
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
The correct answer is: B
