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 Q]: Problem: evaluate 64 / . 08
Options: a ) 800 , b ) 500 , c ) 505 , d ) none of these , e ) 506
[EX A]: a

[EX Q]: Problem: the average age of 15 students of a class is 15 years . out of these , the average age of 8 students is 14 years and that of the other 6 students is 16 years , the age of the 15 th student is
Options: a ) 17 , b ) 12 , c ) 13 , d ) 14 , e ) 15
[EX A]: a

[EX Q]: Problem: a mixture of 50 litres of milk and water contains 10 % water . how many litres of water should be added to the mixture so that the mixture contains 15 % water ?
Options: a ) 15 , b ) 20 , c ) 25 , d ) 30 , e ) 10
[EX A]:
c