OF THE 230 Single HOMES BUILT in city X last year,How many were occupied at the end of the year?
we have to calculate (Number of homes OF the 230 that were occupied at the EOY)
All Single Family Homes = X + 230
where X = OLD Single Family Homes that were built before LAST YEAR
So, statement says
0.9(X + 230) were OCCUPIED at EOY
=> 0.9X + 0.9*230 = > 90% of (230) were OCCUPIED LAST YEAR.
From the question we get:
Total Homes in City X = [Homes built before last year] + 230
We are asked how many of the 230 homes were occupied.
So we also have equation:
230 = [Occupied Homes Built last year] + [Unoccupied Homes Built last year]
Question is, Occupied Homes BUILT LAST YEAR = ?
Statement (1) gives us an entirely new equation that adds even more unknown variables:
Total Homes in City X = Total Occupied(.9) + Total Unoccupied(.1)
We can't do anything with this. Insufficient.
Statement (2) gives us the exact same information from Statement 1 in a different form
Total Homes In City X = 7200 + Total Unoccupied
Even combining these two equations it is impossible to get any information on the homes built last year to answer the question, let alone which ones were occupied. So (C) is also insufficient.
Answer = E.