Answer : The new density and new volume of carbon dioxide gas is 0.2281 g/L and 
 respectively.
Explanation :
First we have to calculate the new or final volume of carbon dioxide gas.
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,

where,
 = initial pressure of gas = 10 kPa
 = final pressure of gas = 15 kPa
 = initial volume of gas = 
 = final volume of gas = ?
 = initial temperature of gas = 
 = final temperature of gas = 
Now put all the given values in the above equation, we get:


The new volume of carbon dioxide gas is 
Now we have to calculate the new density of carbon dioxide gas.

Formula for new density will be:

where,
 = new pressure of gas = 15 kPa
 = new temperature of gas = 
M = molar mass of carbon dioxide gas = 44 g/mole
R = gas constant = 8.314 L.kPa/mol.K
 = new density
Now put all the given values in the above equation, we get:


The new density of carbon dioxide gas is 0.2281 g/L