The equation used for the calculation is P subscript 1 V subscript 1 equals P subscript 2 V subscript 2. Thus, option B is correct.
The pressure of the gas with respect to volume is given with inverse proportion. The ideal gas equation is given as:

<h3>Equation for relation between volume and pressure</h3>
The initial pressure of the gas has been given as, 
The initial volume of the gas has been, 
The final volume of the gas has been, 
The final pressure of the gas,
is given as:

Thus, the equation used for the calculation is P subscript 1 V subscript 1 equals P subscript 2 V subscript 2. Thus, option B is correct.
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