Two blocks are fastened to the ceiling of an elevator that weigh is 100kg and 10kg. The elevator accelerates upward at 2.00 m/s2. Find the tension of the rope.

I don't understand the arrangement of two blocks you're trying to describe. However, for a block tied to the ceiling of the elevator the tension in the rope will equal the block's weight plus F=ma, where a = the acceleration. Thus the total tension is T=m(a+g).