Well Management Private Limited needs a database to help with the maintenance of a

private residential estate. There are various types of apartments in the estate, and the

monthly maintenance fee is based on the apartment type $($single$-$room, double$-$room, threeroom, $4-$room and Penthouse$).$ Each apartment has a block number, unit number, owner's

name, and phone number. The block number combined with the unit number is unique for

each apartment. Each apartment receives a monthly bill at the end of the month. The

monthly bill records the year and month of the bill, the amount due, date due and date paid.

There are facilities in the residential estate. Each facility is identified by the facility type and a

number. For instance: swimming pool $1,$ swimming pool $2,$ playground $1,$ playground $2,$

Reading room $1,$ Reading room $2,$ etc. The condition and service remarks of each facility

must also be recorded. Some facilities require booking and payment for each use. For

instance: tennis court, function room, meeting room, squash court, etc. For the paid facility,

the hourly fee and restriction $($example: max two hours per booking for tennis court$)$ must be

recorded. The booking record includes a reference number $($unique$),$ date of booking, start

time of booking, end time of booking and fee due. Each booking can only reserve one

facility. give me a conceptual schema of the above