Question

Elements of S1 are in ascending order, and those of S2 are in descending order. a24 and a35 are interchanged, then which of the following statements is true?

• A. S1 continues to be in ascending order.
• B. S2 continues to be in descending order.
• C. S1 continues to be in ascending order and s2 in descending order.
• D. None of the above

Answer 1

The correct option is A S1 continues to be in ascending order.

Ans: (a)

Let S1 = 1, 2, 3, 4,......., 24, S2 = 50, 49,........., 25;

New series after interchange S1 = 1, 2, 3, 4........, 25, S2 = 50, 49,.......24

It is therefore clear that S1 continues to be in ascending order.

As this is a variable based question: the word "ANY" can be used

Let the series of integers $a_1,a_2,.......,a_{50}$ be $1,2,3,4,5,......,50.$

$S_1=1,2,3,4,......24,S_2=25,26,27,.........50$