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: a student chose a number , multiplied it by 8 , then subtracted 138 from the result and got 102 . what was the number he chose ? 
Options: a ) 30 , b ) 120 , c ) 130 , d ) 140 , e ) 150
[A]: a


[Q]: Problem: in a renowned city , the average birth rate is 6 people every two seconds and the death rate is 3 people every two seconds . estimate the size of the population net increase that occurs in one day . 
Options: a ) 129,500 , b ) 129,600 , c ) 129,700 , d ) 129,800 , e ) 129,900
[A]: b


[Q]: Problem: the total age of a and b is 10 years more than the total age of b and c . c is how many year younger than 
Options: a ) 14 years , b ) 12 years , c ) 56 years , d ) 10 years , e ) 55 years
[A]:
d