Rahul can finish one-fifth of his homework in one hour. Neha can finish three-sevenths of her homework in one hour thirty minutes and Riya can finish three fourth of her homework in three hours thirty minutes. If all of them start their homework at 12.00p.m 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 3.30p.m for thirty minutes?