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: robert ate 13 chocolates , nickel ate 4 chocolates . how many more chocolates did robert ate than nickel ? 
Options: a ) a ) 4 , b ) b ) 7 , c ) c ) 9 , d ) d ) 5 , e ) e ) 2
[EX A]: c

[EX Q]: Problem: a number is doubled and 5 is added . if the resultant is trebled , it becomes 123 . what is that number ? 
Options: a ) 12 , b ) 29 , c ) 27 , d ) 18 , e ) 99
[EX A]: d

[EX Q]: Problem: having received his weekly allowance , a student spent 3 / 5 of his allowance at the arcade . the next day he spent one third of his remaining allowance at the toy store , and then spent his last $ 0.40 at the candy store . what is this student ’ s weekly allowance ? 
Options: a ) $ 1.20 , b ) $ 1.50 , c ) $ 1.80 , d ) $ 2.00 , e ) $ 2.50
[EX A]:
b