The task is to generate the correct answer for a given math problem.

Q: Problem: a solution of 70 litres contains oil and water in the ratio 9 : x . if 6 litres of water is added to the solution , the ratio becomes 6 : 4 , find the value of x ?

A: 
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Q: Problem: 5 / 8 of 3 / 10 of a number is greater than 4 / 9 of 1 / 4 of the same number by 55 . what is half of that number ?

A: 36
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Q: Problem: the l . c . m of two numbers is 495 and their h . c . f is 5 . if the sum of the numbers is 100 , then their difference is

A:
10
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