At what temperature is the velocity of sound double that of its velocity at $0^{\circ}C$?

Newton assumed that sound propagation in a gas takes place under which condition?

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: $A$ sound wave has higher speed in solids than gases.
Reason $R$: Gases have higher value of Bulk modulus than solids.
In the light of the above statements,choose the correct answer from the options given below:

The ratio of the velocity of sound in hydrogen $\left(\gamma=\frac{7}{5}\right)$ to that in helium $\left(\gamma=\frac{5}{3}\right)$ at the same temperature is

$Assertion :$ The base of Laplace correction was that exchange of heat between the region of compression and rarefaction in air is negligible.
$Reason :$ Air is a bad conductor of heat and the velocity of sound in air is quite large.

Write the equation for the speed of a sound wave according to Newton and explain the correction made by Laplace.