An empty LPG cylinder weighs 14 . 8kg . When full, it weighs 29 ....

Initial mass of gas $= 29 - 14 . 8 = 14 . 2Kg$

mass of gas used : $= 29 - 23 = 6Kg$

gas left $= 14 . 2 - 6 = 8 . 2Kg$

$( 1 ) 3 . 47 \times V = \left(\dfrac{14 . 2 \times {10}^{3}}{M}\right) \times R \times T$

$( 2 ) p \times V = \left(\dfrac{8 . 2 \times {10}^{3}}{M}\right) \times R \times T$

Divide : $( 1 ) / ( 2 ) ⇒ \dfrac{3 . 47}{P} = \dfrac{14 . 2}{8 . 2}$

$P = 2 . 003$