In a row of girls, Nivedita is 15th from the left and Vimla is 23rd from the…
2024
In a row of girls, Nivedita is 15th from the left and Vimla is 23rd from the right. If they interchange their positions, then Nivedita becomes 18th from the left. Then at what position will Vimla be from the right?
- A.
26
- B.
28
- C.
27
- D.
25
Show answer & explanation
Correct answer: A
Concept: When a person's position is known from both the left and the right end of a row, the total number of people in the row is Total = (position from left) + (position from right) − 1 — the −1 removes the double count of that one shared seat. The same identity converts a position from one end to the other for a fixed total: position from the right = Total − position from the left + 1.
After Nivedita and Vimla interchange seats, Nivedita occupies the seat that was originally Vimla's.
This new seat is given as 18th from the left, so Vimla's original position from the left was 18th.
Vimla's original position from the right was already given as 23rd.
Combining these with Total = (left) + (right) − 1 gives the row's total strength: 18 + 23 − 1 = 40 girls.
After the interchange, Vimla occupies the seat that was originally Nivedita's, 15th from the left.
Converting this to a position from the right: Total − (position from left) + 1 = 40 − 15 + 1 = 26.
Cross-check: Nivedita's new position from the right should equal the same 23rd that was already given for Vimla's original seat (since Nivedita now sits in that exact seat). Using the same total: 40 − 18 + 1 = 23, which matches — confirming the total of 40 is correct and Vimla's position from the right is 26.