A) 75 h
B) 65 h
C) 55 h
D) 45 h
E) None of these
Correct Answer: D
Solution :
Undecayed isotope\[=1-\frac{7}{8}=\frac{1}{8}\] \[\frac{N}{{{N}_{0}}}={{\left( \frac{1}{2} \right)}^{t/T}}\] \[\frac{1}{8}={{\left( \frac{1}{2} \right)}^{t/15}}\] \[\frac{t}{15}=3\] \[t=45\,h\]You need to login to perform this action.
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