The average of 24 numbers is 26. The average of the first 15 numbers is 23 and that of the last 8 number is 33. Find the 16$$^{th}$$ number.

Given, the average of the first 15 numbers is 23

$$\Rightarrow$$  Sum of first 15 numbers = 23 x 15 = 345

Average of last 8 numbers is 33

$$\Rightarrow$$  Sum of last 8 numbers = 33 x 8 = 264

Average of 24 numbers is 26

$$\Rightarrow$$  Sum of 24 numbers = 26 x 24 = 624

$$\Rightarrow$$  Sum of first 15 numbers + 16th number + Sum of last 8 numbers = 624

$$\Rightarrow$$  345 + 16th number + 264 = 624

$$\Rightarrow$$  16th number = 15

Hence, the correct answer is Option C