As a result of a series of radioactive decays, uranium 238 92U is converted into lead 206 82Pb. What number

As a result of a series of radioactive decays, uranium 238 92U is converted into lead 206 82Pb. What number of a- and b-decays does he undergo in this case?

Each -decay leads to a decrease in the charge number of the nucleus by 2 and a decrease in the mass number by 4. Each -decay does not change the mass number of the nucleus and increases the charge number of the nucleus by 1. Since the mass number changed to, we conclude that -decay has occurred. A change in the charge number by means that, in addition to 8-decays, β-decays also occurred.
Answer: 86.