In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Example Input: Problem: a tank with a volume of 20 cubic feet has one inlet pipe and 2 outlet pipes . the inlet pipe fills water into the tank at the rate of 5 cubic inches / min and the 2 outlet pipes empty it out at the rates of 9 cubic inches / min and 8 cubic inches / min respectively . if all 3 pipes are opened when the tank is full , how many minutes does it take to empty the tank ? ( 1 foot = 12 inches ) 
Options: a ) 2110 , b ) 2220 , c ) 2440 , d ) 2660 , e ) 2880
Example Output: e

Example Input: Problem: a and b together can do a work in 4 days . if a alone can do it in 20 days . in how many days can b alone do it ? 
Options: a ) 11 , b ) 5 , c ) 6 , d ) 8 , e ) 25
Example Output: b

Example Input: Problem: the speed of a train is 90 kmph . what is the distance covered by it in 15 minutes ? 
Options: a ) 15 , b ) 66 , c ) 22.5 , d ) 52 , e ) 42
Example Output:
c