A license plate in the country Kerrania consists of four digits followed by two letters. The letters A, B, and C are used only by government vehicles while the letters D through Z are used by non-government vehicles. Kerrania's intelligence agency has recently captured a message from the country Gonzalia indicating that an electronic transmitter has been installed in a Kerrania government vehicle with a license plate starting with 79. If it takes the police 9 minutes to inspect each vehicle, what is the probability that the police will find the transmitter within three hours? Choices.
A) 18/79	B) 1/6	C) 1/25	D) 19/900	E) 1/900
Everything is correct except that you assumed the letters can't be repeated. It can be repeated.   AA   BB   CC   AB, AC, BC, BA, CA, CB.   Thus; total government vehicles = (10)^2*(3)^2 = 100*9= 
<gadget id="calculator">100*9</gadget>
<output>900</output>
900   Vehicles inspected within 3 hours= 60*3/9 = 19   P = 19/900   Ans:19/900
<result>D</result>
A license plate in the country Kerrania consists of four digits followed by two letters. The letters A, B, and C are used only by government vehicles while the letters D through Z are used by non-government vehicles. Kerrania's intelligence agency has recently captured a message from the country Gonzalia indicating that an electronic transmitter has been installed in a Kerrania government vehicle with a license plate starting with 79. If it takes the police 9 minutes to inspect each vehicle, what is the probability that the police will find the transmitter within three hours?