The price of a television set was increased by 10% to 2,420. What was the price before the increase

Question

How do you set up the correct ratio and know it's correct by just using the words in the Word problem 

Answer 1

If the price was increased by 10% then the new price is 110% of the original.

110%(P) = 2420   where P is the original price.

1.1P = 2420

P = 2420/1.1

P = $2,200