Each of the offices in a certain building has a floor area of 200, 300, or 350 square feet. How many offices are on the first floor of the building?"

(1) There is a total of 9,500 square feet of office space on the first floor of the building

(2) Ten of the offices on the first floor have floor areas of 350 square feet each.

Pretty straightforward.

1) Tells us nothing about the possible breakup of offices. Could be a number of combinations. INSUFFICIENT.
2) Tells us nothing about total office space or total square footage of other office types. INSUFFICIENT.

Taken together we know 10 @ 350 = 3500, so we have 6000 sq feet remaining, but still could be any combo of 200 and 300 sq foot offices.

It's pretty simple, yes.

Each of the offices in a certain building has a floor area of 200, 300, or 350 square feet. How many offices are on the first floor of the building?

(1) There is a total of 9,500 square feet of office space on the first floor of the building. There are many ways to break 9,500 into the sum of 200's, 300's and 350's. Not sufficient.

(2) Ten of the offices on the first floor have floor areas of 350 square feet each. This just tells that there are more than 10 offices on the first floor. Not sufficient.

(1)+(2) 9,500 - 350*10 = 6,000 square feet on the first floor is occupied by 200 or 300 square feet offices. The same here: there are many ways to break 6,000 into the sum of 200's and 300's. Not sufficient.

Answer: E.
_________________

Yes, the second statement means that there are exactly ten offices with floor areas of 350 square feet.
_________________