scientific Notation $-$ Multiplication and Division

Simplify and write in Scientific Notation, rounding to $2$ decimal places as needed.

a$.(2\mathrm{.}504{10}^{15})(8\mathrm{.}726{10}^{16})=$

b$.\frac{3\mathrm{.}175{10}^{-8}}{9\mathrm{.}963{10}^{-13}}=$