Assume you need to create a database to hold the information on a
fleet of cars and in particular the major compo4nents of the cars
(wheels, engine, brakes..), their replacement costs and theoritical
life(amount of time or kilometres that they will last).
The main purpose of this database will be to a) hold an inventory of
the vehicles, and b) to calculate into the future how much the fleet
will cost every month based on the replacement costs and theoretical
life of each part. (e.g. Tires need to be replaced every 80,000km, and
on average a car will do 4,000km per month....)
 
1. What will your main database tables be?
 
2. What data fields will they contain?
 
3. What is the SQL statement and/or flowchart to calculate and return
the future monthly costs.
 
 
4. What technology would you recommend to build the front end with and why?

I hope this is the answer you're looking for:
1+ 2. Table: Vehicle
Fields: VehicleId
 	EngineId
	BreakId
	WheelFrontRId
	WheelFrontLId
	WheelBackRId
	WheelBackLId	
	

Table: Parts
Fields: PartsId
	Type (eg. Tyre, brake,?)
Replacement costs 
Theoretical life

3.
SELECT 
SUM(Replacement costs/( Theoretical life/4000)) 
FROM Vehicle LEFT JOIN Parts 
ON 
		EngineId = PartsId OR
	BreakId = PartsId OR
	WheelFrontRId = PartsId OR
	WheelFrontLId = PartsId OR
	WheelBackRId = PartsId OR
	WheelBackLId = PartsId
     	WHERE
		VehicleId = <some input>;

4. What technology you want to use depends how a lot of things. How
many (concurrent) users? What kind of backend are you using? What is
the computerknowledge of the users? Do you want to spend money?
When you?re not yet have choosen a backend you can try mysql with an
php front-end, this is very easy to learn, and for free so you can
experiment a bit before deciding if you?re gonna use this.