Guy has helped you to calculate as follows,
first of all you have to check is there any
possibility to get accomodation at this rate
A studio aprtment will cost you anywere 4500-5000QRS.

Accommodation - 3500
water/elect - 200
dsl/cable - 300
food - 1500
kids expense incl school - 1000
clothing - 300
car loan - 1100
petrol - 200
soap, tpaste etc - 300
others - 600
TOTAL = QR 9000