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: a certain number of horses and an equal number of men are going somewhere . half of the owners are on their horses ' back while the remaining ones are walking along leading their horses . if the number of legs walking on the ground is 40 , how many horses are there ? 
Options: a ) 8 , b ) 12 , c ) 14 , d ) 16 , e ) 18
[EX A]: a

[EX Q]: Problem: if a * b * c = ( √ ( a + 2 ) ( b + 3 ) ) / ( c + 1 ) , find the value of 6 * 15 * 2 . 
Options: a ) 8 , b ) 5 , c ) 11 , d ) 3 , e ) 4
[EX A]: e

[EX Q]: Problem: in a school with 5 classes , each class has 2 students less than the previous class . how many students are there in the largest class if the total number of students at school is 140 ? 
Options: a ) 28 , b ) 29 , c ) 30 , d ) 31 , e ) 32
[EX A]:
e