A property company sold 20% more houses in 2007 than in 2006. If the company sold 426 houses in 2007, calculate how many houses it sold in 2006. Show every step.

Here's how to work this type of problem. If the company sells A items in year 1, and then sells x% more in year 2, the amount sold in year two is equal to the amount sold in year 1 plus 25% more:

B = A + x% x A = A(1+x)

For example: if you sell 60 units in year 1, and sales increase 25% in year 2, then the amount sold in year 2 is 60 x (1+ 0.25) = 75 units.

Now turn it around - if the company sold 75 units in year 2, and you are told this is a 25% gain from year 1, then the amount sold in year 1 was 75/(1.25) = 60.

Now, can you apply this same technique to your problem?