bhumika.k.shah wrote:If the total cost of a housing project with f units is $1,750,000, what was the cost per unit for the housing project?
(1) If half as many units were built for the same total price, the cost per unit would be $250,000.
(2) If six more units had been built for the same total price, the cost per unit would be $3,750 less.
Why is A not sufficient?
The question is plainly about finding f.
Ideally, the two statements on the real GMAT DS never contradict each other. So, either it's NOT a cushy average problem or NOT a GMAT one. It is always recommended to go through both statements of a DS problem on GMAT before making a decision. Our general interpretation about statement (1) of this problem proves to be off beam or dubious when we switch to statement (2) with the same mindset as it was used in statement (1) of this problem.
If it were a plain average problem, then statement (1) alone was sufficient, and we would never have needed to go for the C option of DS. But, at the same time, if it was correct that way then the statement (2) must NOT have contradicted it on the real GMAT.
The number of units stated in statement (2) is got to be a positive integer, in fact 20, if you have memories from statement (1) still intact. Statement (1), as treated so far, got us the information that the cost per unit for the housing project in the main question is $125,000 and that there were 14 units built in the housing project. Therefore statement (2) says that 20 units were built @ $(125,000 - 3,750) or $121250 per unit to cost $1,750,000; and no one of us would be agree to take that 20 * $121250 = $1,750,000.
Easiest way out is to hiss the source and move ahead. But we should come back to it, later, if needed, may be.
The mind is everything. What you think you become. -Lord Buddha
Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001
www.manyagroup.com