Yeah. cause if he painted half a room in half a day that means in a whole day he painted a whole room. so in 7 whole days he should paint 7 whole rooms :)
You have to use the equation which has just slipped my mind. It say x1-y1 over x2-y2. Then you will find x. I am so sorry this equation name slipped my mind. If I remember I will let you know.
