Sam Clara invited 9 of his friends to his house to sing karaoke, The average time of each song is exponentially distributed with a mean of 4 minutes. Usually, when one finishes his/her song, he/she will wait and rest for an average of 16 minutes to sing the next song, and this time is also exponential What is the average time each person has to wait to sing if they have 2 karaoke microphone? (keep 2 decimal places) Sam Clara invited 9 of his friends to his house to sing karaoke, The average time of each song is exponentially distributed with a mean of 4 minutes. Usually, when one finishes his/her song, he/she will wait and rest for an average of 16 minutes to sing the next song, and this time is also exponential What is the average time each person has to wait to sing if they have 2 karaoke microphone? (keep 2 decimal places)