How many neutrons does element x have if its atomic number is 41 and its mass number is 162?

The Protons and Electrons are equal to the atomic number (41). And the mass number (162) is equal to the sum of the number of protons and neutrons in the nucleus. So to find the number of Neutrons, just subtract 41 (number of protons) from 162 (mass). That means element X has 121 Neutrons.

Icant be totally sure but i would say with confidence that it is example #1 about cells.