Don't worry about hours. Many who have recently started on the 737 bring around 250 hrs in the logbook and just finished their ratings.
The questions are similar to a type rating exam multiple choice. Few are a bit tricky, few are quite simple. Just as a hint from my side:
- Study the airconditioning system a bit, esp. switch position for bleeds on/off takeoff
- Take a glance at the emergency exit lights, what powers them, what happens if some of the elec power is lost,
- Look at the elec system roughly, you dont need to be an expert but as i recall there were some questions (look at the power sources for the stby busses...)
- Isolation valve, how operated, what is electrical, what is pneumatic
- Fuel pumps, AC or DC powered
- Fire Detection and Extinguishing system....what is DC powered, what is AC powered
If you run into troubles during the questionnaire, just as a hint, try to analyze by yourself what is really needed in an emergency or abnormal situation and what power sources are needed to run. It helps once in a while to differ between AC and DC powered systems.
Take a look at the flows (no matter how you learned it), it gives you a picture about normal switch positions and when they are used.
And BTW, we run short of 737 pilots with rating (as far as i know) and the pile of rated people is decreasing, the number of aircraft and routes increasing.
Hope that helped a bit
Best Luck, hb