[patrickyeon]

Speed of light, baby! IIRC, on the order of 4 hours from Pluto. 16 hours (one-way) out to Voyager 1 where it is now.

[ralfd]

Wolfram Alpha excels in that type of questions:

http://www.wolframalpha.com/input/?i=distance+pluto+%2F+ligh...

http://www.wolframalpha.com/input/?i=distance+voyager+1+%2F+...

P.S. You are correct.