<s>[INST] Three friends with the names Amy, Bob and Charlotte, are trying to figure out how many miles they each have left on their rounds. They know that Amy has some number of miles left (let that be $n$), Bob has 2 miles more than Amy (or $n+2$) and Charlotte has $n/2$ miles (rounded up to the nearest whole number) miles left.
A.) Find all positive integer values for $n$, where all three of them have a whole number of miles left to run.
B.) If all three friends average 6 miles per hour, and that is a constant speed, then what is the amount of time it would take for all three friends to finish their rounds?[/INST]