In a sample of $100$ heart patients, each patient has $80 \%$ chance of having a heart attack without medicine $\mathrm{X}$. It is clinically known that medicine $\mathrm{X}$ reduces the probability of having a heart attack by $50 \%$. Medicine $\text{X}$ is taken by $50$ of these $100$ patients. The probability that a randomly selected patient, out of the $100$ patients, takes medicine $\mathrm{X}$ and has a heart attack is
- $40 \%$
- $60 \%$
- $20 \%$
- $30 \%$