Verbal Reasoning - Mental Ability Questions

P is the brother of Q. Q is the brother of R. P is the son of S. Based these three statements, much of the following statements cannot be definitely true?

In a row of swimmers Manish, is 23rd from the left end. Ramesh is 11 ranks to the left of Manish. If Ramesh is 16th from right end, then how many swimmers are there in this row?

In the following question, select the related number from the given alternatives.
48 : 63 : : 80 : ?

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

8 ÷ 6 - 5 + 70 x 10 = ?

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

45 x 5 + 2 - 20 = ?

Two rugby players start running from the same place on the pitch. Player A runs 20 m South, then turns to his left and runs 26 m. In the mean while Player B runs 12 m West, then he runs 6 m South, the he turns to his left and runs 38 m. Where is Player A with respect to Player B?

A man starts from point 'O', travels 20 km towards east to reach point 'A', turns right and travels 10 km to reach point 'B', turns right and travels 9 km to reach point 'C', turns right and travels 5 km to reach point 'D', turns left and travels 12 km to reach point 'E' and then turns right and travels 6 km to reach point 'F'.

What is the shortest distance between point 'E' and point 'C'?

While posing for a family photo, the father is standing to the right of the son and left of the grandmother. The mother is sitting to the left of her daughter and right of the grandmother. Who is seated in the middle?