I'd say 90 mph for the return trip, but it has been a long time since I took math. And do you have to allow for how many red lights you hit on the return trip?
You'd probably have to go faster than 90 mph on the return trip to make up for the time you lose while the cop is writing you a speeding ticket.
“Warp speed?”
I spent way too much time with time and distance averaging and harmonic averaging...
CRAP! If only I was smart, I could have been a contender!!!
Clearly Warp speed would do it!!!
Damn.