In a certain code language, '123' means 'hot filtered coftee' ; '356' means 'very hot day' and '589' means 'day and night'. Which digit stands for 'very' ?

Answer: E. 6

In the first and second statements, the common code digit is '3' and the common word is 'hot'.
So, '3' means 'hot'.
In the second and third statements, the common code digit '5' and the common word is 'day'.
So, '5' means 'day'.
Thus, in the second statements, '6' means 'very'.