![](https://cos-cdn.shuashuati.com/pipixue-wap/2020-1230-1107-56/ti_inject-812ce.png)
The results of previous data analysis show that when the machine is adjusted well, the qualified rate of products is 90%, while when the machine fails, the qualified rate is 30%. Every morning when the machine is started, the probability of the machine adjusted well is 75%. Try to find out the probability of the machine failure when the first product in the morning is known to be qualified