Verbal Reasoning - Mental Ability Questions

In a certain code language, '+' represents 'x', '-' represents '+', 'x' represents '÷' and '÷' represents '-'. What is the answer to the following question?
642 x 6 ÷ 25 + 4 = ?

In the following series, one number is missing as shown by the question mark. Select the missing number from the given options.

8, 12, 16, 20, ?

In the following question, from the given alternative words, select the word which cannot be formed using the letters of the given word.
Passenger

A series is given with one term missing. Choose the correct alternative from the given ones that will complete the series.

14, 19, 29, 44, ?

What is total number of triangles in the given figure?

Find the missing number?

In a certain code language, '-' represents 'x', '÷' represents '+', '+' represents '÷' and 'x' represents '-'. Find out the answer to the following question.

2 x 12 ÷ 32 - 5 + 4 = ?

A series is given with one term missing. Select the correct alternative from the given ones that will complete the series.

BMX, DNW, FOV, ?