Question

At any instant, the ratio of the amount of radioactive substance is 2 : 1. If their half lives be respectively 12 and 16 hours, then after two days, what will be the ratio of the substance

• A. 1:1
• B. 2:1
• C. 1:2
• D. 1:4

Answer 1

The correct option is A

1:1

$N_1=\frac{2N_0}{2^{\frac{2\times 24}{12}}},N_2=\frac{N_0}{2^{\frac{2\times 24}{16}}}$

$N_1=\frac{2N_0}{2^4},N_2=\frac{N_0}{2^3}$

$\frac{N_1}{N_2}=\frac{1}{1}$