In this task, you need to provide the correct option for a given problem from the provided options.
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Question: Problem: a jar contains a mixture of two liquids acid ( nitric acid ) and base ( ammonium chloride ) in the ratio 4 : 1 . when 10 litres of the mixture is taken out and 10 litres of liquid base is poured into the jar , the ratio becomes 2 : 3 . how many litres of liquid acid was contained in the jar ? 
Options: a ) 14 lts , b ) 18 lts , c ) 20 lts , d ) 16 lts , e ) 26 lts

Answer: d


Question: Problem: there are 8 executives , including the ceo and cfo , that are asked to form a small team of 4 members . however , the ceo and cfo may not both be assigned to the team . given this constraint , how many ways are there to form the team ? 
Options: a ) 45 , b ) 55 , c ) 65 , d ) 75 , e ) 85

Answer: b


Question: Problem: solution a is 20 % salt and solution b is 60 % salt . if you have 30 ounces of solution a and 60 ounces of solution b , in what ratio could you mix solution a with solution b to produce 50 ounces of a 50 % salt solution ? 
Options: a ) 6 : 4 , b ) 6 : 14 , c ) 4 : 4 , d ) 4 : 6 , e ) 1 : 3

Answer:
e