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.
--------
Question: Question: The average marks of a class of 35 students is 45 and that of another class of 55 students is 65. Find the average marks of all the students?

 Option A: 52.6

 Option B: 52.4

 Option C: 52.1

 Option D: 57

 Option E: 52.9

Answer: Option D


Question: Question: If x and y are negative integers, which of the following statements must be true?
I. (-x)^y is positive.
II. (-x)^(-y) is positive.
III. x^(-y) is positive.

 Option A: None

 Option B: II only

 Option C: I and II

 Option D: I and III

 Option E: I, II and III

Answer: Option C


Question: Question: In traveling from a dormitory to a certain city, a student went 1/3 of the way by foot, 3/5 of the way by bus, and the remaining 2 kilometers by car. What is the distance, in kilometers, from the dormitory to the city?

 Option A: 30

 Option B: 45

 Option C: 60

 Option D: 90

 Option E: 120

Answer:
Option A