Help with algebra homework?

[lifton]

On a 255 mile trip mark traveled an average speed of 70mph, got a speeding ticket , and then traveled at 60 mph for the remainder of the trip. If the entire trip took 5.4 hours and the speeding ticket stop took 30 minutes how long did mark speed before getting stopped?
how do I solve this? help?

[egan]

x is how long he spent going 70 mph
5.4-.5(for stopping)=total time traveling=4.9
so he spent 4.9-x time going 60mph
70x+60(4.9-x)=255
70x+294-60x=255
10x=-# OOPS!!
I think your numbers must be wrong-even if he traveled 60 mph the whole time he would have gone more than 255 miles!!!