You can do the math - a dreamliner has two engines, each burning 2-3 tonnes of fuel an hour when cruising, depending on weight & altitude. The longest scheduled dreamliner flight is something like 15 hours, so it works out to about 75 tonnes of fuel if you take the midpoint of 2500kg/hr/engine. Stated fuel capacity is about 100 tonnes which includes some extra for climb out & reserve. So it looks about right to me.