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.
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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: A, B, C are three consecutive positive integers (A>B>C). What is the value of the expression 2A +B +2C?

Option A: 6A+7.

Option B: 5A+1.

Option C: 5A-5.

Option D: 6A-5.

Option E: 6A-7.

Answer: Option C

Question: Question: Laura took out a charge account at the General Store and agreed to pay 7% simple annual interest. If she charges $35 on her account in January, how much will she owe a year later, assuming she does not make any additional charges or payments?

Option A: $2.10

Option B: $37.10

Option C: $37.45

Option D: $38.10

Option E: $38.80

Answer:
Option C