Material for an earth fill was available from three different borrow pits$/$sites$.$ In the

compacted state the fill measured $1\mathrm{.}0$x $105$ m$3$

at void ratio of $0\mathrm{.}75.$ The corresponding insitu void ratio and cost $($cost of material and transportation$)$ of the material for three sites

are as follows:

Borrow site Void ratio Total cost per cubic meter

$10\mathrm{.}8$ Rs$.200$

$21\mathrm{.}15$ Rs$.180$

$31\mathrm{.}25$ Rs$.175$

Determine the most economical site for the above earth fill wor