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: how many integerskgreater than 100 and less than 1100 are there such that if the hundreds and the units digits ofkare reversed , the resulting integer is k + 99 ? 
Options: a ) 50 , b ) 60 , c ) 70 , d ) 80 , e ) 90
[A]: e


[Q]: Problem: how many paying stones , each measuring 2 1 / 2 m * 2 m are required to pave a rectangular court yard 20 m long and 16 1 / 2 m board ? 
Options: a ) 66 , b ) 18 , c ) 16 , d ) 10 , e ) 15
[A]: a


[Q]: Problem: the sum of ages of 5 children born at theintervals of 3 years each is 50 years . what is the age of the youngest child ? 
Options: a ) 4 , b ) 5 , c ) 9 , d ) 8 , e ) 10
[A]:
a