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: 5 drainage pipes , each draining water from a pool at the same constant rate , together can drain a certain pool in 16 days . how many additional pipes , each draining water at the same constant rate , will be needed to drain the pool in 4 days ? 
Options: a ) 6 , b ) 9 , c ) 10 , d ) 12 , e ) 15

Answer: e


Question: Problem: find the ones digit of 73 ^ 356 
Options: a ) 1 , b ) 5 , c ) 6 , d ) 7 , e ) 9

Answer: a


Question: Problem: in a fuel station the service costs $ 1.75 per car , every liter of fuel costs 0.65 $ . assuming that a company owns 12 cars and that every fuel tank contains 55 liters and they are all empty , how much money total will it cost to fuel all cars ? 
Options: a ) 320 $ , b ) 380 $ , c ) 420 $ , d ) 450 $ , e ) 480 $

Answer:
d