Answer
$6 \times 10^5$
Work Step by Step
RECALL:
$a^m \cdot a^n = a^{m+n}$
Multiply the corresponding parts and use the rule above when necessary to obtain:
$=(2\cdot3) \times (10^3 \cdot 10^2)
\\=6 \times 10^{3+2}
\\=6 \times 10^5$