ANSWER
$16,384
EXPLANATION
From the question we have that,
Nadir saves $1 the first day of a month, $2 the second day, $4 the third day, and so on.
This forms a geometric sequence,
The first term of this sequence is
The common ratio is
The general term of a geometric sequence is given by the formula:
To find the 15th term, we plug in a=1, r=2 and n=15.
The amount he will save on the 15th day is $16,384