Task: Question Answering
Input (English): Problem: x , a , z , and b are single digit positive integers . x = 1 / 8 a . z = 1 / 8 b . ( 10 a + b ) – ( 10 x + z ) could not equal 
Options: a ) 28 , b ) 35 , c ) 49 , d ) 63 , e ) 55
Output (English): e