Which of the following graphs represents Boyle's law?

$A$ gas has a volume of $3.4 \ L$ at $25^{\circ} C$. What is the final temperature if the volume increases to $10.2 \ L$ at constant pressure (in $K$)?

The gas equation $PV = nRT$ is obeyed by:

Equal amounts of gases are kept in two separate containers. If the densities of the two gases are in $1:2$ ratio and their temperatures are in $2:1$ ratio, calculate the ratio of their respective pressures.

Pay load is defined as the difference between the mass of displaced air and the mass of the balloon. Calculate the pay load when a balloon of radius $10 \, m$,mass $100 \, kg$ is filled with helium at $1.66 \, bar$ at $27^{\circ} C$. (Density of air $= 1.2 \, kg \, m^{-3}$ and $R = 0.083 \, bar \, dm^{3} \, K^{-1} \, mol^{-1}$).

$A$ gas cylinder can withstand a pressure of $15 \ atm$. At $27 \ ^oC$,the pressure in the cylinder is $12 \ atm$. Up to what temperature in $^oC$ will the cylinder not burst?