Question: What is the postcode of a town in Cook County, New South Wales, that is situated approximately 100 km west of the Sydney central business district, and about 8 km east of Katoomba?
Related documents: [0]  [DOC] Wentworth Falls (postcode: 2782) is a town in the Blue Mountains region of New South Wales, situated approximately 100 km west of the Sydney central business district, and about 8 km east of Katoomba, Australia on the Great Western Highway, with a Wentworth Falls railway station on the Main Western line. The town is at an elevation of 867 m   . At the 2011 census , Wentworth Falls had a population of . [END] 
[1]  [DOC] Cook County was one of the original Nineteen Counties in New South Wales and is now one of the 141 Cadastral divisions of New South Wales. It includes the area to the west of Sydney in the Blue Mountains, between the Colo River in the north, and the Coxs River in the south and west, encompassing Lithgow, Mount Victoria, Katoomba, Wentworth Falls, Lawson and most of the other towns in the Blue Mountains. The Nepean River is the border to the east. Before 1834, the area was part of the Westmoreland, Northumberland and Roxburgh counties. [END] 
Answer: 
2782
2782