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: each of the products produced yesterday was checked by worker x or worker y . 0.5 % of the products checked by worker x are defective and 0.8 % of the products checked by worker y are defective . if the total defective rate of all the products checked by worker x and worker y is 0.7 % , what fraction of the products was checked by worker y ? 
Options: a ) 2 / 3 , b ) 5 / 6 , c ) 7 / 8 , d ) 4 / 5 , e ) 5 / 8
[EX A]: a

[EX Q]: Problem: if the radius of a cylinder is doubled and height 5 times , what is the new volume of the cylinder divided by the old one ? 
Options: a ) 8 . , b ) 2 . , c ) 6 . , d ) 20 . , e ) 10 .
[EX A]: d

[EX Q]: Problem: at deluxe paint store , fuchsia paint is made by mixing 5 parts of red paint with 3 parts of blue paint . mauve paint is made by mixing 3 parts of red paint with 5 parts blue paint . how many liters of blue paint must be added to 40 liters of fuchsia to change it to mauve paint ? 
Options: a ) 9 , b ) 12 , c ) 15 , d ) 16 , e ) 26.6
[EX A]:
e