7.5 x 10-4
7.5 x 10-3
7.5 x 10-2
7.5 x 10-1
Correct answer is B
\(\frac{0.3 \times 10^5}{0.4 \times 10^7} = \frac{3 \times 10^{-1} \times 10^{5}}{4 \times 10^{-1} \times 10^7}\)
\(\frac{3 x 10^4}{4 x 10^4}\)
\(\frac{3}{4}\) x 104-6 = 0.75 x 10-2
= 7.5 x 10-3