Visa fee

Hi, I want travel to China for about 4 weeks with my childrens(British passport). How much should i pay if i submit personally in the ofice?? GBP30 or GBP 30 + GBP 36= GBP 76 per person? Is that necessary i need to bring along my childrens for applying for the visa in the office??? the photo requirements is same as Uk passport??