Question

The activity per ml of solution of radioactive substance is x how much water be added to 200 ml of the solution so that activity falls to x upon 20 per ml after 45 flights

Answer 1

Answer:

$N=N_{0} (\frac{1}{2} )^{n}$

$(\frac{xv}{20} )=(x)*200(\frac{1}{2} )^{4}$

V=250ml

so added volume of water=50ml