In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
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Question: Problem: in a river flowing at 2 km / hr , a boat travels 40 km upstream and then returns downstream to the starting point . if its speed in still water be 6 km / hr , find the total journey time . 
Options: a ) 10 hours , b ) 12 hours , c ) 14 hours , d ) 15 hours , e ) none of these

Answer: d


Question: Problem: ? x 24 = 173 x 240 
Options: a ) 545 , b ) 685 , c ) 865 , d ) 1730 , e ) 534

Answer: d


Question: Problem: the number 189 is equal to the sum of the cubes of two integers . what is the product of those integers ? 
Options: a ) 8 , b ) 15 , c ) 20 , d ) 27 , e ) 39

Answer:
c