Salika travels to school by train every day. The probability that her train will be late on any day is 0.3. If salika is late on 4 consecutive days she gets a detention. what is the probability she will get a detention during a week?
we would draw a tree diagram to show this. 4 consecutive days means everyday except friday, or everyday except monday. this would be 2(0.3x0.3x0.3x0.3x0.7)