Answer
$$2.4\times 10^{-15}.$$
Work Step by Step
By adding the exponents and multiplying the like terms, we have
$$ (4 \times 10^{-6})(6 \times 10^{-10})= (4 )(6 ) \times 10^{-6-10}
\\
=24\times 10^{-16}=2.4\times 10^{-15}.$$
You can help us out by revising, improving and updating this answer.
Update this answerAfter you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.