Let the two numbers be \( x \) and \( y \) such that \( x > y \). Then, \( x \times y = 9375 \) and \( \frac{x}{y} = 15 \). Solving these equations, we find \( x = 375 \) and \( y = 25 \). Thus, the sum of the numbers is:
\[
x + y = 375 + 25 = 400
\]
(Note: There appears to be a typographical error in the options provided based on the calculation, the correct sum is 400 as derived from the problem setup.)