“Stationary waves conduct energy”. True or False?

In a standing wave on a string $:-$

The speed of a stationary wave represented by the equation $y = 0.7 \sin \left(\frac{7 \pi}{4} x\right) \cos (350 \pi t)$ is (In the given equation $x$ and $y$ are in metre and $t$ is in second). (in $m \ s^{-1}$)

Spacing between two successive nodes in a standing wave on a string is $x$. If the frequency of the standing wave is kept unchanged but the tension in the string is doubled,then the new spacing between successive nodes will become

$A$ stationary wave is formed having $4$ nodes along the $120 \,cm$ length of the string. The wavelength of the wave is (in $\,cm$)

Standing waves are produced in a $10 \; m$ long stretched string. If the string vibrates in $5$ segments and the wave velocity is $20 \; m/s$,the frequency is ... $Hz$.