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: 0.002 x 0.6 = ? 
Options: a ) 0.0012 , b ) 0.001 , c ) 0.01 , d ) 0.1 , e ) none of these
a

Problem: if ( x + 3 ) ^ 2 / ( 2 x + 15 ) = 3 , then the difference between the two possible values of x is : 
Options: a ) 8 , b ) 10 , c ) 12 , d ) 14 , e ) 16
c

Problem: s ( n ) is a n - digit number formed by attaching the first n perfect squares , in order , into one integer . for example , s ( 1 ) = 1 , s ( 2 ) = 14 , s ( 3 ) = 149 , s ( 4 ) = 14916 , s ( 5 ) = 1491625 , etc . how many digits y are in s ( 99 ) ? 
Options: a ) y = 350 , b ) y = 353 , c ) y = 354 , d ) y = 356 , e ) y = 357

b