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'.

Problem: a dog is tied to a tree by a long nylon cord . if the dog runs from the due north side of the tree to the due south side of the tree with the cord extended to its full length at all items , and the dog ran approximately 30 feet , what was the approximate length of the nylon cord e , in feet ? 
Options: a ) 30 , b ) 25 , c ) 15 , d ) 10 , e ) 5
d

Problem: the tax on a commodity is diminished by 40 % but its consumption is increased by 25 % . find the decrease percent in the revenue derived from it ? 
Options: a ) 18 % , b ) 72 % , c ) 25 % , d ) 12 % , e ) 52 %
c

Problem: when greenville state university decided to move its fine arts collection to a new library , it had to package the collection in 20 - inch by 20 - inch by 12 - inch boxes . if the university pays $ 0.50 for every box , and if the university needs 2.16 million cubic inches to package the collection , what is the minimum amount the university must spend on boxes ? 
Options: a ) $ 155 , b ) $ 225 , c ) $ 510 , d ) $ 850 , e ) $ 1250

b