Question

Cynthia can wallpaper a room in 4 hours and her brother can do it in 6 hours. How long would it take them if they work together

​

Answer 1

2 hours and 24 minutes

Explanation:

cynthia can wallpaper a room 4 hours with means in 1 hour she can wallpaper 1/4th of the room, her brother can wallpaper the same room in 6 hours so I'm 1 hour he can wallpaper 1/6 of the room.