How can i loose 10kg weight fast in just 3 weeks by which exercise should i do ? my weight is 60kg and height is 154cm and i'm 20 years old .

It won't happen: Ten Kg is the equivalent of 66,000 calories & most people consume/use 2000-3000/day. You could run/walk & workout constantly and increase your metabolic burn to 4000/day but would have no other life. You would also have to cut your diet down to 400 cal/day. None of this would be healthy & should only be done under supervision. If you cut back eating & workout some, 1kg/wk would be reasonable.