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'.

[Q]: Problem: if a : b = 2 : 3 , b : c = 4 : 5 and c : d = 5 : 9 then a : d is equal to : 
Options: a ) 11 : 17 , b ) 8 : 27 , c ) 5 : 9 , d ) 2 : 9 , e ) none
[A]: b


[Q]: Problem: how many even 4 - digit numbers can be formed , so that the numbers are divisible by 4 and no two digits are repeated ? 
Options: a ) 336 , b ) 784 , c ) 1120 , d ) 1804 , e ) 1936
[A]: c


[Q]: Problem: an engineer designed a ball so that when it was dropped , it rose with each bounce exactly one - half as high as it had fallen . the engineer dropped the ball from a 16 - meter platform and caught it after it had traveled 32.5 meters . how many times did the ball bounce ? 
Options: a ) 2 , b ) 6 , c ) 7 , d ) 8 , e ) 9
[A]:
a