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 age of 3 boys is 15 years and their ages are in the proportion 1:2:3. The age of the youngest boy is?

 Option A: 10 years

 Option B: 12 years

 Option C: 15 years

 Option D: 18 years

 Option E: 7.5 years

A: Option E
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Q: Question: If each of 4 digit code is formed of integers from 1 to 50, inclusively, and each of the digits are different, how many possible codes are there?

 Option A: 5527200

 Option B: 5586300

 Option C: 5598600

 Option D: 5547800

 Option E: 2569800

A: Option A
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Q: Question: How many seconds will a 700 metre long train take to cross a man walking with a speed of 3 km/hr in the direction of the moving train if the speed of the train is 63 km/hr?

 Option A: 25

 Option B: 30

 Option C: 42

 Option D: 45

 Option E: 50

A:
Option C
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