Ricky can finish 1/5 of his homework in 1 hour, Jane can finish 3/7 of her homework in t four 30 minutes and Ann can finish 3/4 of her homework in 3 hours 30 minutes. All of them start their homework at 1200 hours and can go to play as soon as they all finish their homework. When can they start to play, if they take a break at 1530 hours for 30 minutes?