How many tanks are there on an A350? Where are they located? Is it a common configuration among large aircraft?
In addition to Farhan's answer, we can also say that A350-900ULR (Ultra Long Range) version, capable of 20 hours of non-stop flights and up to 9,700 nautical miles, or 1,600 more than the standard A350-900, integrates a modified fuel system, which increases the aircraft’s fuel carrying capacity by 24,000 litres without the need for additional fuel tanks, increasing fuel carrying capacity from 141,000 litres to 165,000 litres.
Benefitting from the A350-900’s unique flexibility, the extended range capability does not involve installation of additional fuel tanks, but rather an adaptation of the fuel system within the existing fuel tank.