Tom, working alone, can paint a room in 6 hours. Peter and John, working independently, can paint the same room in 3 hours and 8 hours, respectively. Tom starts painting the room and works on his own for one hour. He is then joined by Peter and they work together for an hour. Finally, John joins them and the three of them work together to finish the room, each one working at his respective rate. What fraction of the whole job was done by Peter?  Choose the correct choice from the following choices
A) 7/15 B) 11/25 C) 17/35 D) 23/45 E) 27/55
Tom paints 1/6 of the room in the first hour.   Tom and Peter paint 1/6+1/3 = 1/2 of the room in the next hour for a total of 4/6.   The three people then paint the remaining 2/6 in a time of (2/6) / (15/24) = 8/15 hours   Peter worked for 23/15 hours so he painted 23/15 * 1/3 = 23/45 of the room.   The answer is 23/45.
<result>D</result>
Tom, working alone, can paint a room in 6 hours. Peter and John, working independently, can paint the same room in 3 hours and 8 hours, respectively. Tom starts painting the room and works on his own for one hour. He is then joined by Peter and they work together for an hour. Finally, John joins them and the three of them work together to finish the room, each one working at his respective rate. What fraction of the whole job was done by Peter?