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 13 minutes to inspect each vehicle, what is the probability that the police will find the transmitter within three hours? Choose the correct choice
A) 18/79 B) 1/6 C) 1/60 D) 1/50 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*3/13 = 15   P = 15/900 = 1/60   Ans:1/60
<result>C</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 13 minutes to inspect each vehicle, what is the probability that the police will find the transmitter within three hours?