The number of atoms in an end-centered unit cell are 2. This is because in each end centered unit cell, there are 8 atoms at the eight corners of the cube, and one atom each is present at the centre of any two opposite faces.
Total number of atoms in one unit cell
= 8 corner atoms X (1/8) atom per unit cell + 2 face-centred atoms X (1/2) atom per unit cell
= 1 + 1