15.6.6 Definition and properties of probability

Problem: \( 30 \% \) of the patients at the hospital have disease \( K \), \( 20 \% \) of the patients have disease \( L \), and the rest of the patients have disease \( M \). The probabilities that the patients with diseases \( K, L, M \) will be discharged healthy, are equal to respectively 0,5 ; 0,\( 4 ; 0,9 \). Find the probability that a healthy patient who was discharged had disease \( K \).