You are given a math word problem and you are supposed to make use of mathematical concepts like probability, combinatorics, linear equations, sequences/series, or simple operators like addition, subtraction, division, or multiplication to answer the given question. Choose the best option from the 5 given options and report that option.

[Q]: Question: If the line L passes through the point (3,n) and (n,3), where n is not equal to 3, which of the following must be true?
1. Line L must passes through the first quadrant
2. Line L does pass the origin
3..The slope of L is negative

 Option A: I only

 Option B: II only

 Option C: III only

 Option D: I and II

 Option E: II and III
[A]: Option C


[Q]: Question: The length of a room is 7 m and width is 4.75 m. What is the cost of paying the floor by slabs at the rate of Rs. 900 per sq. metre.

 Option A: 25650

 Option B: 25750

 Option C: 26550

 Option D: 26750

 Option E: 29925
[A]: Option E


[Q]: Question: A boat goes 6 km up stream and 7 km down stream in 5 hours. It goes 3 km up stream and 6 km down stream in 3 hours. The speed of the boat in still water is:

 Option A: 2 km/hr

 Option B: 5.4 km/hr

 Option C: 4.8 km/hr

 Option D: 3.33 km/hr

 Option E: None of these
[A]:
Option D