divide £700 by the number of nights 2X2 =4 3x4 = 12 to get a per night plus 2X7 =14 so total 30 nights @23.33 per night call it £25 so the ladies spending 2 nights pay £50 each, the ladies spending 4 pay 100 and the other two pay 175 each giving £50 spare to pay for a few bottles of wine on the nights you are all together