Answer:
[tex]3.84 * 10^{9}[/tex]
Step-by-step explanation:
[tex]\\\\(1.2 * 10^{4}) * (3.2 * 10^{5}) = 1.2 * 3.2 * 10^{4} * 10^{5} = 3.84 * 10^{4+5} = 3.84 * 10^{9} \\\\[/tex]