Answer:
 $15,000
Step-by-step explanation:
The amount of simple interest is computed using the formula ...
 I = Prt
where I is the interest earned; P is the principal invested at rate r for time period t.
Fill in the given information and solve for P.
 $2625 = P·0.035·5
 $2625/0.175 = P = $15,000
Samuel deposited $15,000 in the account.