Supply and Demand: End of Chapter Problem

Your roommate just bought a Garmin GPS Smartwatch for $$155\mathrm{.}00.$ She wanted a device that could improve her morning runs by measuring the speed, distance, and duration of the runs, and calculating her calories burned. She would have been willing t pay $$250\mathrm{.}00$ for a device that could accomplish these tasks. How much consumer surplus does your roommate enjoy from the Smartwatch?

I

Consumer surplus $=$$