answer:**Analysis** This question examines the simple properties of a parabola, focusing on the application of the definition of a parabola and highlighting the examination of transformation ideas. It is a basic question. By using the definition of a parabola, the distance from point (A) to the focus being (4) can be transformed into the distance from point (A) to its directrix. **Solution** Given that the equation of the directrix of the parabola (y^{2}=2px(p > 0)) is (x=- dfrac{p}{2} ), and the focus (F( dfrac{p}{2} ,0)), and the distance from the point (A(2,m)) on the parabola (y^{2}=2px(p > 0)) to the focus is (6), Therefore, by the definition of a parabola, the distance from point (A(2,m)) to the focus is equal to its distance to the directrix, Thus, (2-(- dfrac{p}{2} )=4), Therefore, (p=4). Hence, the answer is boxed{4}.

answer:First, perform the operation inside the parentheses: [ 10 div 2 = 5 ] Next, perform the division outside the parentheses: [ 150 div 5 = 30 ] Finally, add 5 to the result: [ 30 + 5 = boxed{35} ]

answer:**Analysis** This question mainly examines the relationship between the monotonicity of a function and the sign of its derivative, which is a basic problem. First, we need to find the derivative of the function f(x), then set the derivative less than 0 to find the range of x. **Solution** Given f(x)=x-ln x, we have f'(x)=1- frac{1}{x}= frac{x-1}{x}. Let frac{x-1}{x} < 0, then we get 0 < x < 1. Therefore, the answer is: boxed{{x|0 < x < 1}}.

answer:1. Recognize that the room numbers are in sequential order from 1 to 30. 2. Remove the unoccupied room numbers 16, 17, and 18. 3. The remaining room numbers are 1-15 and 19-30, making a total of 27 numbers. 4. To find the median of these 27 numbers, we need the 14th number in this new sequence since there are 13 numbers on either side. 5. Counting the rooms, the sequence before 16 is 1 to 15 (15 numbers) and after 18 is 19 to 30 (12 numbers). The 14th room, counting sequentially without skipping, falls in the original sequence: - Since room 15 is the 15th number, room 19 becomes the 16th. Thus, the 14th number in the modified list is room 14. Thus, the median room number of the participants that showed up is boxed{14}.