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'.

Ex Input:
Problem: if 1 / 12 of the passengers on a ship are from north america , 1 / 4 are europeans , 2 / 9 are from africa , 1 / 6 are from asia and the remaining 50 people are citizens of other continents , then how many passengers are on board the ship ? 
Options: a ) 120 , b ) 140 , c ) 150 , d ) 160 , e ) 180

Ex Output:
e


Ex Input:
Problem: a 20 litre mixture of milk and water contains milk and water in the ratio 3 : 2 . 10 litres of the mixture is removed and replaced with pure milk and the operation is repeated once more . at the end of the two removal and replacement , what is the ratio t of milk and water in the resultant mixture ? 
Options: a ) 17 : 3 , b ) 9 : 1 , c ) 3 : 17 , d ) 5 : 3 , e ) 11 : 2

Ex Output:
b


Ex Input:
Problem: if you write down all the numbers from 1 to 100 , then how many times do you write 3 ? 
Options: a ) 11 , b ) 18 , c ) 20 , d ) 21 , e ) 22

Ex Output:

c