Question: Can you guide me through solving this problem: A factory used to make tractors, but now makes silos. When they made tractors, they sold 10 tractors a day and made $100 per tractor. Now, they sell 5 silos a day, and make $220 per silo. What percentage more are they making per day now?
Answer: 
They used to make $1,000 a day because 10 x 100 = 1,000
They now make 1,100 a day because 5 x 220 = 1,100
They make 10% more per day because 1000 +(1000 x (X/100)) = 1,100 if X = 10