A woman has 7 keys. only one of them will open her door. when seh arrives at the door there is no sufficient light for her to fi
nd the correct key. if she tries one key at a time and discards the keys that don't work, what is the probability that she will open the door with the first key she picks? what is the probability that it will take exactly three attempts to open the door? suppose that the first three attempts to open the door have been unsuccessful. what is the probability that she will pick the right key the fourth time?
Since she has seven key the probability that the first one will open the door is if it takes three attempts to open the door,the probability is if the three attempts would not work then the probability that the fourth attempt will open the door is hope this helps
If you draw out a coordinate plane you will see that they , on their Y access, are both nine witch means that they a horizontal line so all you have to do is subtract the x access witch is 3.
