JEE Main 2013 Physics question

The half-life of a radioactive element A is the same as the mean-life of another radioactive element B. Initially both substances have the same number of atoms, then :

• (1)A and B decay at the same rate always.
• (2)A and B decay at the same rate initially.
• (3)A will decay at a faster rate than B.
• (4)B will decay at a faster rate than A.Correct