Verbal Reasoning - Mental Ability Questions

In the following question, select the number which can be placed at the sign of ? from the given alternatives.

In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question?
25 + 10 ÷ 240 x 16 = ?

A piece of paper is folded and punched as shown below in the question figures. From the given answer figures, indicate how it will appear when opened?

Find out the odd word/letters/number/number pair from the given alternatives.

A series is given, with one number missing. Choose the correct alternative from the given ones that will complete the series.
6, 18, 54, ? , 486, 1458

If '+' means '/', '/' means '­','­' means 'x', 'x' means '+', then 24+8/2­6x6=?

If IRON is written as GOKI, then KNIFE may be written as