How many lengandary Pokemon are there in Pokemon white?

Answer 1

Nine, Zekrom/Reshiram (depending on which game you have)

Victini get by wireless thing

Cobalion you need surf to get to Mistraltron Cave

Terrakion somewhere on Victory road when you Cobalion a cave opens up

Virizion somewhere in pinwheel forest a new area has appeared when you have obtained Cobalion

Kyurem when you go to Giant chasm there is a small lake you will hear a roar when you get to it snow will come then head north and look for a cave

Tornadus/Thundurus you will hear strange weather reports on route 7 then you will see one of them (Depending on the game) but it will fly away and appear in different places depending on the time of day

Landorus after obtaining both Tornadus and Thundurus by trading go to abundant shrine just of route fourteen

For more information go to Serebii.net