Radioactive isotopes often occur together in mixtures. Suppose a 480 sample contains , with a half-life of 12 days, and , with a half-life of 4.5...

Radioactive isotopes often occur together in mixtures. Suppose a 480 sample contains , with a half-life of 12 days, and , with a half-life of 4.5 days. If there are initially twice as many calcium atoms as there are barium atoms, what will be the ratio of calcium atoms to barium atoms 2.90 weeks later?