PhysicsEasy183×since 2002Q6130If a radioactive element having half-life of 30 min30 \mathrm{~min}30 min is undergoing beta decay, the fraction of radioactive element remains undecayed after 90 min90 \mathrm{~min}90 min. will beA116\frac{1}{16}161B14\frac{1}{4}41C18\frac{1}{8}81D12\frac{1}{2}21Check answerSkip