Verbal Reasoning - Mental Ability Questions

Find the missing number in the series

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

7 x 10 ÷ 30 - 2 + 6 = ?

In the following question, by using which mathematical operators will the expression become correct?
15 _ 3 _ 4 _ 20

A marathon route starts and goes 21 km North, then there is a turn towards West where the route goes on for 7 km, then there is a turn towards North where the route goes on for 10 km, then there is a right turn from where the route goes on 7 km to reach the end. Where is it now with reference to its starting position?

A man starts from a point, walks 5 km towards East, turns right and walks 3 km, turns right again and walks. What is the direction he is facing now?

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

3, 9, 4, 16, 5, ?

If "*" denotes "added to", "&" denotes "divided by", "@" denotes "multiplied by" and "%" denotes "subtracted from", then 399 & 19 @ 21 % 41 * 100 = ?

Select the missing number from the given options?