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'.
--------
Question: Problem: the toll for crossing a certain bridge is $ 0.75 each crossing . drivers who frequently use the bridge may instead purchase a sticker each month for $ 11.00 and then pay only $ 0.30 each crossing during that month . if a particular driver will cross the bridge twice on each of x days next month and will not cross the bridge on any other day , what is the least value of x for which this driver can save money by using the sticker ? 
Options: a ) 14 , b ) 15 , c ) 16 , d ) 28 , e ) 29

Answer: e


Question: Problem: the number 152 is equal to the sum of the cubes of two integers . what is the product of those integers ? 
Options: a ) 8 , b ) 15 , c ) 21 , d ) 27 , e ) 39

Answer: b


Question: Problem: if a and b are positive real numbers , and a ^ 3 + b ^ 3 = 20 , then the greatest possible value of a is between : 
Options: a ) 0 and 3 , b ) 3 and 4 , c ) 4 and 5 , d ) 5 and 7 , e ) 7 and 9

Answer:
a