Distance Time word problem

Hi Guys,

I am having trouble figuring out this distance time word problem. I created a table and show my reasoning below but I am getting some weird answers. Can you guys please point out where I am going wrong? Thanks.

A car leaves town X at 0800 and arrives at town Y at 0915. During the first hour of the journey, the car travels at a constant speed of 80 km/h. If the average speed of the car between 0815 and 0915 is 2 km/h less than the average speed for the whole journey, find

(a) the distance of the journey from town X to town Y,

(b) the average speed between 0815 and 0915.

Here's my reasoning. I figured that if I assume x is the speed between 0900 to 0915 and then using the condition part of 2nd sentence, I would be able to solve for x. Here's the table I built,

Then, Avg Speed is

And given,

Solving that equation gives me x = 1900 km/h!!!

Please help!, Where am I going wrong?

P.S. First time using this Latex stuff :), Thanks to great tutorial here.