Be more specific. Like what is it asking you to do ? I'm trying to help. :)
.231 .232 .233 hope this helps ;D
Your choice of answer D is correct.
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When the number of days is zero, the height is 130 inches. This eliminates choices B and C. Evaluating the expression for n=13 gives
... 130 + 13×13 = 130 + 169 = 299 . . . . . corresponding to answer D.