Answer : The temperature needed for the same amount of gas would be, 997.2 K
Explanation :
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 = 6 atm
= final pressure of gas = 1 atm
= initial volume of gas = 18 mL
= final volume of gas = 300 mL
= initial temperature of gas =

= final temperature of gas = ?
Now put all the given values in the above equation, we get:


Thus, the temperature needed for the same amount of gas would be, 997.2 K