Answer
$$6.4\times 10^{7}$$
Work Step by Step
By subtracting the exponents and dividing the like terms and then by raising each factor to the exponent and multiplying the double exponents, we have $$\left(\frac{1.2\times 10^{-2}}{3\times 10^{-5}}\right)^3=(0.4\times 10^{3})^3=0.064\times 10^{9}\\ =6.4\times 10^{7}$$ which is in the scientific notation.
