In a certain code, '256' means 'you are good' ; '637' means 'we are bad' and '358' means 'good and bad'. Which of the following represents 'and' in that code ?

Answer: C. 8

In the first and third statements, the common code digit is '5' and the common word is 'good'
So, '5' means 'good'.
In the second and third statements, the common code digit is '3' and the common word is 'bad'.
So, '3' means 'bad'.
Thus, in third statement, '8' means 'and'.