Average of all even numbers between 222 and 250 is . . . . . . . .

Answer: Option C

$$\begin{array}{rl}& \text{Numbers are }224,226,.....248\\ & S_n=\frac{13}{2}\left[224+248\right]\\ & =\frac{13}{2}\times 472\\ & \text{Average}=\frac{13\times 472}{2\times 13}=236\\ & \\ & \mathbf{Alternate}:\\ & \text{Average of all even number between }222\text{ and }250\\ & \Rightarrow a=224\\ & l=248\\ & \text{Average}=\frac{a+l}{2}\\ & =\frac{224+248}{2}\\ & =236\end{array}$$