Open Question: Math Help Work Rate.?
2:33 Publicado por Nadim
These are always give in hours per room, just change them to fraction of room per hour.
Mr S. 1 room in 3 hours, so he does 1/3 room per hour.
His assistant needs 5 hours, so he does 1/5 room per hour.
After 1 hour, Mr S has done 1/3 of the room, leaving 2/3 for his assistant.
His assistant has to do 2/3 room at 1/5 room/hr, so (2/3)/(1/5) = 5*2/3 = 10/3 or 3-1/3 hours or 3 hours, 20 minutes.
0 comentarios:
Publicar un comentario