+77 A schoolboy wakes up late on average of 3 days in every 5 days. If he wakes up late, the probability that he is late for school is 9/10 . If he does not wake up late, the probability that he's late for school is 3/10 . On what percentage of days does he get to school on time?
+9673 P(get to school on time)
= 1 - P(late for school)
= \(1- \left(\dfrac{3}{5}\times \dfrac{9}{10}+\dfrac{2}{5}\times \dfrac{3}{10}\right)\\ \)
= 17/50
Therefore percentage of days he gets to school on time is 17/50 x 100% = 34%
+12531 A schoolboy wakes up late on average of 3 days in every 5 days. If he wakes up late, the probability that he is late for school is 9/10 . If he does not wake up late, the probability that he's late for school is 3/10 . On what percentage of days does he get to school on time?
