The average of eight numbers is 20. The average of five of these numbers is 18. The average of the remaining three numbers is

Correct option is D

Given:
Average of 8 numbers = 20
Average of 5 numbers = 18
Formula Used:
Average = $$\frac{\text{Sum }}{ \text{Number of elements}}$$​​
Sum = Average $$\times$$​ Number of elements
Solution:
Sum of 8 numbers = Average of 8 numbers $$\times$$​ 8 = 20$$\times$$ 8 = 160
Sum of 5 numbers = Average of 5 numbers$$\times$$ 5 = 18 $$\times$$ 5 = 90​​
Sum of 3 numbers = Sum of 8 numbers - Sum of 5 numbers = 160 - 90 = 70
Average of 3 numbers = $$\frac{\text{Sum of 3 numbers }}{ 3 }$$​= $$\frac{70 }{3 }$$​= 23.33 (approximately)

Thus, option (D) is correct.