Question

Find the value of $\sqrt{10}\times \sqrt{15}$.

Answer 1

$\sqrt{10}\times \sqrt{15}$

$$\begin{gathered} =\sqrt{5\times 2}\times \sqrt{5\times 3} \\ =\sqrt{5\times 5\times 3\times 2}\left[\because \sqrt{a}\times \sqrt{b}=\sqrt{ab}\right] \\ =5\sqrt{6} \end{gathered}$$

So, $\sqrt{10}\times \sqrt{15}=5\sqrt{6}$.