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'.

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
d

Problem: the average monthly income of p and q is rs . 2050 . the average monthly income of q and r is rs . 5250 and the average monthly income of p and r is rs . 6200 . the monthly income ofq is : 
Options: a ) 1100 , b ) 2100 , c ) 1200 , d ) 3100 , e ) 1300
a

Problem: in an examination , the percentage of students qualified to the number of students appeared from school a is 70 % . in school b , the number of students appeared is 20 % more than the students appeared from school a and the number of students qualified from school b is 50 % more than the students qualified from school a . what is the percentage of students qualified to the number of students appeared from school b ? 
Options: a ) 30 % , b ) 70 % , c ) 80 % , d ) 87.5 % , e ) none

d