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: 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

A: Option D
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Q: Question: A sum of Rs.4800 is invested at a compound interest for three years, the rate of interest being 10% p.a., 20% p.a. and 25% p.a. for the 1st, 2nd and the 3rd years respectively. Find the interest received at the end of the three years?

 Option A: Rs.3129

 Option B: Rs.3120

 Option C: Rs.3108

 Option D: Rs.3106

 Option E: Rs.3127

A: Option B
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Q: Question: A vessel of capacity 2 litre has 40% of alcohol and another vessel of capacity 6 litre had 60% alcohol. The total liquid of 8 litre was poured out in a vessel of capacity 10 litre and thus the rest part of the vessel was filled with the water. What is the new concentration of Mixture?

 Option A: 31%.

 Option B: 44%.

 Option C: 49%.

 Option D: 29%.

 Option E: 51%.

A:
Option B
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