A certain roller coaster has 7 cars, and a passenger is equally likely to ride in any 1 of the 7 cars each time that passenger rides the roller coaster. If a certain passenger is to ride the roller coaster 7 times, what is the probability that the passenger will ride in each of the 7 cars?
Choose the correct choice from the following answers:
A) 0	B) 1/9	C) 2/9	D) 720/16807	E) 1
If he is to ride 6 times and since he can choose any of the 6 cars each time, total number of ways is   = 7 * 7 * 7 * 7 * 7 * 7= 
<gadget id="calculator">7 * 7 * 7 * 7 * 7 * 7</gadget>
<output>117_649</output>
117649   Now the number of ways if he is to choose a different car each time is= 7 * 6 * 5 * 4 * 3 * 2 * 1= 
<gadget id="calculator">7 * 6 * 5 * 4 * 3 * 2 * 1</gadget>
<output>5_040</output>
5040   So the probability is= 5040/117649 = 720/16807   Answer : 720/16807
<result>D</result>
A certain roller coaster has 7 cars, and a passenger is equally likely to ride in any 1 of the 7 cars each time that passenger rides the roller coaster. If a certain passenger is to ride the roller coaster 7 times, what is the probability that the passenger will ride in each of the 7 cars?