# The average income of 40 persons is 4200 Rs. and that of an other 35 persons is 4000 Rs. The average income of the whole group is :

The average income of 40 persons is 4200 Rs. and that of an other 35 persons is 4000 Rs. The average income of the whole group is :
[A]$4108 \frac{1}{3}Rs.$
[B]$4106 \frac{2}{3}Rs.$
[C]$4100 Rs.$
[D]$4106 \frac{1}{3}Rs.$

$\mathbf{4106 \frac{2}{3}}Rs.$
Average income of whole group =
$= \frac{4200\times 40+4000\times 35}{75}$
$= \frac{168000+140000}{75}$
$= \frac{308000}{75} = 4106\frac{2}{3}Rs.$
Hence option [B] is the right answer.