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

Solution (By Examveda Team)

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