First of all, I must assume that the correct cost for carpet is $4.25 per square foot.
It could be $4.25 per foot if it came of a standard roll, but then I would need to know the width of the roll, which you haven't given.
Area of the room = (15-ft x 14-ft) = 210 square feet
Area of the closet = (4-ft x 8-ft) = 32 square feet
Total area = (210 + 32) = 242 square feet.
Total cost of carpet = (242 x $4.25) = $1,028.50 plus pad and installation.
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You know what ? I think you may have mis-copied the price of carpet altogether.
At $4.25 per square foot, that's awfully expensive carpet.
I suspect the actual price is $4.25 per square yard. That's pretty cheap, but
it's a lot closer to reasonable than $4.25 per square foot is ($38.25 per yd² !)
If it's $4.25 per square yard, then we need to know that 1 square yd = 9 square ft.
The total requirement is 242/9 = 26 and 8/9 square yard, so you'll buy 27 sq yds.
$4.25 x 27 = $114.75 plus pad and installation. That sounds cheap but better.