A and B alone can complete a work in 24 and 48 days respectively. If 50% of the work is completed by C in 3x days and remaining work is completed by A and B working together in x days, then find the time taken by B and C together to complete the work. 1) 20 days 2) 24 days 3) 16 days 4) 18 days 5) None of these