ratio 9:13:18......added = 40. This means that one person gets 9/40 of the total, one person gets 13/40 of the total and one person gets 18/40 of the total.
and if the total is 800...
9/40 * 800 = 7200/40 = 180 <==
13/40 * 800 = 10400/40 = 260 <==
18/40 * 800 = 14400/40 = 360 <==
