In a certain code language, 'ACQUIRE' is written as 'QCAUERI', 'ADDRESS' is written as 'DDARSSE', and 'ABILITY' is written as 'IBALYTI'. How will 'ICEBERG' be written in that language?

ECIBGRE

The logic followed here is;

(first letter is interchanged with 3rd and 5th is with 7th)

So, that's how we get; 

 'ACQUIRE' is written as 'QCAUERI'

And,

(with same pattern)

'ADDRESS' is written as 'DDARSSE'.

Similarly,

'ICEBERG' be written as ECIBGRE