1 year =52 week working week =52-4=48 (4 week holiday’) working hour=48*35=1680 (1 week=35h) chargeable working hour=1680*90% =1512 total cost =3000+18000=21000 cost per hour=21000/1512=13.88 cost for job =13.89*3 = 41.67 ( number of hour* cost per hour)