What is the expected time in years to find a key by

Question

Question :

Suppose that we have a computer that can test 2⁴⁰ keys each second.

What is the expected time (in years) to find a key by exhaustive search if the keyspace is of size 288?

What is the expected time (in years) to find a key by exhaustive search if the keyspace is of size 2¹¹²?

What is the expected time (in years) to find a key by exhaustive search if the keyspace is of size 2²⁵⁶?