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: the age of somu is one - third his father ' s . 10 years back he was one - fifth of his father ' s age . what is his persent age ? 
Options: a ) 11 , b ) 13 , c ) 14 , d ) 12 , e ) 20
[A]: e


[Q]: Problem: find the principle on a certain sum of money at 5 % per annum for 3 1 / 5 years if the amount being rs . 870 ? 
Options: a ) rs . 700 , b ) rs . 780 , c ) rs . 750 , d ) rs . 1000 , e ) none of these
[A]: c


[Q]: Problem: the sum of two numbers is 528 and their h . c . f is 33 . the number of pairs of numbers satisfying the above condition is 
Options: a ) 4 , b ) 5 , c ) 6 , d ) 7 , e ) 8
[A]:
a