What is the value of the ratio of density $(d)$ to molar mass $(M)$ for an ideal gas?

At constant temperature,in a given mass of an ideal gas,

$100 \, g$ of an ideal gas is kept in a cylinder of $416 \, L$ volume at $27^{\circ} C$ under $1.5 \, bar$ pressure. The molar mass of the gas is $.... \, g \, mol^{-1}$. (Nearest integer) (Given : $R = 0.083 \, L \, bar \, K^{-1} \, mol^{-1}$)

In the equation $PV = nRT$,which one cannot be the numerical value of $R$?

The densities of two gases are in the ratio $1:2$ and their temperatures are in the ratio $2:1$. What is the ratio of their corresponding pressures?

Under what conditions will a pure sample of an ideal gas not only exhibit a pressure of $1 \, atm$ but also a concentration of $1 \, mol \, L^{-1}$ $(R = 0.082 \, L \, atm \, mol^{-1} \, K^{-1})$?