Task 486

The task

Automobile license plates for a state consist of four letters followed by a dash and two single digits. How many different license plate combinations are possible if exactly one letter is repeated exactly once, but digits cannot be repeated? [asy] size(150); draw((0,0)--(0,5)--(10,5)--(10,0)--cycle); label("\Huge{CHIC - 03}",(1,3)--(9,3),S); label("\small\emph{State of Excellence}",(1,1)--(9,1),S); draw((0.5,3.5)--(0.5,4.5)--(2,4.5)--(2,3.5)--cycle); label("\footnotesize 5-03",(1.25,4)); draw((9.5,3.5)--(9.5,4.5)--(8,4.5)--(8,3.5)--cycle); label("\footnotesize FX",(8.75,4)); [/asy]