#"LPG contains 60% propane and 40% butane "#
#:."10L LPG contains 6L propane and 4L butane "#
The balanced equations of the gaseous combustion reactions
#C_3H_8(g)+5O_2(g) -> 3CO_2(g)+4H_2O(g).....(1)#
#2C_4H_10(g)+13O_2(g)-> 8CO_2(g)+10H_2O(g)......*2)#
By equation(1)
1L Propane on combustion produces 3L #CO_2(g)#
#"6L Propane on combustion produces "(3xx6)=18L" " CO_2(g)#
By equation(2)
2L Butane on combustion produces 8L #CO_2(g)#
#"4L Butane on combustion produces "(8xx4)/2=16L" " CO_2(g)#
So the total volume of #CO_2(g)# added on combustion of 10 L LPG will be (18+16)=34L