Hi BlueDragon2010,
The GMAT routinely presents questions that test the thoroughness of your thinking (and this is often the case in DS questions).
Here, we're told that the average price of 3 houses = $120,000; this means that the sum of the 3 houses = $360,000. We're asked for the median value of the 3 houses, which means we need to figure out the "middle" of the 3 values.
Fact 1: Tom's house was $110,000
This tells us that the OTHER 2 houses sum to $250,000.
The 3 houses COULD be:
110,000; 120,000; 130,000 and the median would be $120,000
90,000; 110,000; 160,000 and the median would be $110,000
Fact 1 is INSUFFICIENT
Fact 2: Jane's house was $120,000
This tells us that the OTHER 2 houses sum to $240,000. This is an interesting piece of information because it means that either all the houses cost $120,000 OR one costs more and one costs less than $120,000
The 3 houses COULD be:
100,000; 120,000; 140,000 and the median would be $120,000
120,000; 120,000; 120,000 and the median would be $120,000
No matter how we set the prices, the median is always $120,000
Fact 2 is SUFFICIENT
Final Answer: B
GMAT assassins aren't born, they're made,
Rich