liability/(odds -1 )


For example a 100 hrose would be layed for 30/(100-1) = 30/99 = 0.30

Or at $5 odds it is 30/(5-1) = 30/4 = $7.50

Working back 7.50*$5-$7.5 = $30

Sorry based above on $30 ... just substitue $20 for 30 in above calcs.