Question

Rationalise the denominator in $\frac{5}{3\sqrt{3}}$

• A. $\frac{5\sqrt{3}}{3}$
• B. $\frac{5\sqrt{5}}{9}$
• C. $\frac{5\sqrt{1}}{9}$
• D. $\frac{5\sqrt{3}}{9}$

Answer 1

The correct option is D

$\frac{5\sqrt{3}}{9}$

The least rationalising factor of $\frac{5}{3\sqrt{3}}$ is $\sqrt{3}$

So, we multiply the numerator and denominator by $\sqrt{3}$ which gives

$\frac{5\times \sqrt{3}}{3\sqrt{3}\times \sqrt{3}}$

$=\frac{5\sqrt{3}}{9}$