1536. In the workshop, two motors operate independently of each other. The probability that the first motor will not require the master's attention during an hour is 0.9, and for the second motor, this probability is 0.85. Find the probability that during the hour neither motor will require the master's attention.
Solution. Let $A$ be the event that the first motor will not require attention within an hour, and $B$ be the event that the second motor will not require attention. We need to find $P(A B)$. Since $A$ and $B$ are independent events, $P(A B)=P(A) P(B)=0.9 \cdot 0.85=0.765$.