Thank you for reporting, we will resolve it shortly
Q.
Two identical strings $X$ and $Z$ made of same material have tension $T _{ X }$ and $T _{ Z }$ in them. It their fundamental frequencies are $450 Hz$ and $300 \,Hz ,$ respectively, then the ratio $T _{ x } / T _{7}$, is :
$f =\frac{1}{2 \ell} \sqrt{\frac{ T }{\mu}}$
For identical string $l$ and $\mu$ will be same
$f \propto \sqrt{ T }$
$\frac{450}{300}=\sqrt{\frac{ T _{ x }}{ T _{ y }}}$
$\frac{ T _{ x }}{ T _{ y }}=\frac{9}{4}=2.25$