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?

54 x 9 - 3 ÷ 4 = ?

In a certain code language, “STOINS” is written as “ROHPST”. How is “MARCUS” written in that code language?

Introducing a girl, a man says, "She is the daughter of my father's daughter". How is the girl related to the man?

In the following question, select the related word pair from the given alternatives.

Grandmother : Female : : ? : ?

Rahul moves 5 km towards south and then takes a left turn to move 5 km more. Again, he takes a left turn and moves 10 km and finally, he moves 5 km towards west. In which direction is he now from his initial position?

Select the missing number from the given responses?

In the following question, select the missing number from the given series.21, 26, 33, 42, 53, ?

The weights of 4 boxes are 80, 60, 90 and 70 kilograms. Which of the following cannot be the total weight, in kilograms, of any combination of these boxes?