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: in township k each property is taxed at 10 percent of its assessed value . if the assessed value of a property in township k is increased from $ 20,000 to $ 28,000 , by how much will the property tax increase ? 
Options: a ) $ 800 , b ) $ 1000 , c ) $ 600 , d ) $ 400 , e ) $ 500
[EX A]: a

[EX Q]: Problem: a father said to his son , ` ` i was as old as you are at the present at the time of your birth ' ' . if the father ' s age is 52 years now , the son ' s age 5 years back was : 
Options: a ) a ) 14 , b ) b ) 67 , c ) c ) 56 , d ) d ) 21 , e ) e ) 34
[EX A]: d

[EX Q]: Problem: the average of numbers 0.64205 , 0.64203 , 0.64202 and 0.64201 is ? 
Options: a ) 0.64202 , b ) 0.64204 , c ) 0.642022 , d ) 0.642028 , e ) none
[EX A]:
d