Hi parry,
Rounding can be done with any digit of a number (to the left of the decimal or to the right of the decimal) - and the rules are the same:
The digits 0-4 are rounded DOWN.
The digits 5-9 are rounded UP.
For example...
12.63 rounded to the nearest TENTH is 12.6 (since '3' is rounded down)
12.63 rounded to the nearest INTEGER is 13 (since '6' is rounded up)
12.63 rounded to the nearest TEN is 10 (since '2' is rounded down)
In this question, we're told that X is an INTEGER. We're asked for the value of X.
1) X rounded to the nearest hundred is 7,200.
With this Fact, X could be a variety of different integers (any integer from 7150 to 7249, inclusive)
Fact 1 is INSUFFICIENT
2) The hundreds digit of x is 2.
This Fact tells us that X is at least 200, but it could be ANY number with a 2 in the 'hundreds place' (re: 200, 207, 3214, etc.)
Fact 2 is INSUFFICIENT
Combined, we know...
X rounded to the nearest hundred is 7,200.
The hundreds digit of x is 2.
We still have multiple possibilities here (any integer from 7200 to 7249, inclusive), so we still don't know exactly what X is.
Combined, INSUFFICIENT
Final Answer: E
GMAT assassins aren't born, they're made,
Rich