(Originais Teachy 2023) - Question Easy of Chemistry

Uranium-235, a natural isotope of uranium, undergoes alpha radioactive decay to transform into thorium-231, which in turn decays beta to form protactinium-231. Knowing that uranium-235 has a half-life of 7.04x10^8 years for alpha decay and thorium-231 has a half-life of 25.5 hours for beta decay, determine the time required for 40% of an initial sample of uranium-235 to transform into protactinium-231. Consider that the decays are independent of each other and that the initial sample contains a very large number of uranium-235 atoms, so the quantity of atoms does not change significantly during the period considered.