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 compound ratio of 1:3, 3:2 and 4:5?

Option A: 1:9

Option B: 1:7

Option C: 1:2

Option D: 2:5

Option E: 1:4

A: Option D
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Q: Question: A coin is tossed two times. What is the probability that there is at the least one tail?

Option A: 3/4

Option B: 31/37

Option C: 31/18

Option D: 31/10

Option E: 31/19

A: Option A
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Q: Question: A man can row a distance of 6 km in 60 min with the help of the tide. The direction of the tide reverses with the same speed. Now he travels a further 20 km in 10 hours. How much time he would have saved if the direction of tide has not changed?

Option A: 2

Option B: 8

Option C: 1

Option D: 6:41

Option E: 5

A:
Option D
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