The stimulus says: 450 < x < 550 and 350 < y < 450.

(1) x < 500, so x could be 499.9999, but we'll use 499 for the discussion. 499 + 449 = 948, which is closest to 900. But if we use 451 + 351 = 802, then it is closer to 800. Insufficient.

(2) y < 400. We can use a scenario similar to the one above and figure out that this statement alone isn't sufficient either. Insufficient.

Together, we can try another set of numbers.

499 + 399 = 898, closer to 900.

451 + 351 = 802, closer to 800.

So it is still insufficient. Answer must be E.

By the way, GMAT purposely try to confuse us by writing the question in a wordy and complicated way.

The question could be written as: x rounds to 500 and y rounds to 400, what does x + y round to?

Nicely Done!! Thanks!!

Unbelievable at first i thought that x is also a multiple of 100 and i was getting C. But i just assumed that piece of info.

bkobilov wrote:Please help. Can't understand the question itself.

If 500 is the multiple of 100 that is closest to x and 400 is the multiple of 100 that is closest to y, which multiple of 100 is closest to x+y?
1. x<500
2. y<400

OA: E

i dont know if my comprehense about this data correctly but i think the question itself is weird, imposiible. it saus
500=100*a and a<x and 400=100*b and b<y
thus i think a must be smaller than 5 and b must be smaller than 4
thus this question is imposible... i selected E

I am pretty certain that is not what the question is asking. Closest to multiple of 100's mean 100, 200, 300, 400, 500.

So if X is closest to 500, then it is between 450 and 550.