nope... its 42 kg (14kg each).
It depends upon the driving style too.
I've Santro Club 2003 (50 KG cylinder).
It gives me around 120 KMs with A/C in City (I mean full time A/C on). But some times around 100 KMs in case if I switch the A/C on and stay in the Car for an hour or so specially when I go to shopping with my family
Without A/C easily 150KMs in City.
Long route at speed 120 or 120+ with A/C (120 KMs)
Long route at speed 100 or 110 with A/C (150 KMs)
Long route at speed 120 or 120+ without A/C (140 KMs)
Long route at speed 100 or 110 without A/C (170 KMs)
But if you push your car little hard for example in City 1st gear 30, 2nd gear 60, 3rd gear 100 then it would give you around 110 in city ...