In a row at a bus stop, A is 7th from the left and B is 9th from the right. They both interchange their positions. A becomes 11th from the left. How many people are there in the row?

(A) 18 (B) 19 (C) 20 (D) 21

Solution follows here:

A is 7

(A) 18 (B) 19 (C) 20 (D) 21

Solution follows here:

Solution:

__Initial positions:__

^{th}from left and B is 9^{th}from right and it is not clear about number of people between A and B
_ _ _ _ _ _

__A__?__B___ _ _ _ _ _ _ ___Positions after interchange of A and B:__

A
is 7

^{th}from left
_ _
_ _ _ _

__B___ _ ___A___ _ _ _ _ _ _ _
After
interchange of A and B positions, it is very clear that there are

**19**people in total.

**"The Smarter Approach"**
A's new position = B's old position

Let us concentrate on this position only.

"9th from right and 11th from left"

this means ---> 8 persons to the right and 10 persons to the left of that position.

Including that position, the total count = 8+10+1 = 19

**Answer (B)**

20 is the answer.

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