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

Answer: 


Question: Problem: students at a school were on average 180 cm tall . the average female height was 170 cm , and the average male height was 184 cms . what was the ratio a of men to women ?

Answer: 5 : 2


Question: Problem: 5 % of ( 25 % of $ 1600 ) is ?

Answer:
$ 20