The Half-Life of a Radioactive Material Is $4.5$ Days How Many Days Are Required for a Sample, with Many

Multiple Choice

The half-life of a radioactive material is $4.5$ days. How many days are required for a sample, with an initial activity of $1.0 \times 10 ^ { 5 } \mathrm {~Bq}$ , to decay to an activity of $100 \mathrm {~Bq}$ ?

A) 45 days
B) 54 days
C) 31 days
D) 36 days