60. The radioactive isotope 226Ra decays to 222 Rn with a half-life of 1600 years. The radioactive isotope 238U decays to 234 Th with a half-life of 4.5× 109 years. What is the ratio of the decay rate of 1 g Ra 226 to that of 10 g U 238 ?
(A) 3.0 × 106
(B) 3.0 × 10-7
(C) 3.0 × 105
(D) 3.0 × 10-6
(E) 3.0 × 107
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