91Ó°ÊÓ

The half-life of a response is the time expected for a reactant to arrive at the one-a portion of its underlying fixation or tension. For a first-request response, the half-life is autonomous of fixation and consistent after some time.

In $3$days the number of half-lives is,

$\frac{3days}{3days}×1halflife$= $1$half-life

Hence after one half-life,

localid="1653360684431" $\frac{72}{2}=36megabecquerels$

The half-life of a response is the time expected for a reactant to arrive at the one-a portion of its underlying fixation or tension. For a first-request response, the half-life is autonomous of fixation and consistent after some time.

The number of half-lifes in $6$days is,

$\frac{6\text{days}}{3\text{days}}×1\text{half life}=2\text{halflifes}$

Hence after every one half-life,

$=\frac{72}{2}=36\text{megabecquerels}$

$=\frac{36}{2}=18\text{megabecquerels}$
Hence the number of half lifes in$6$days is$18$megabecqurels.