In a row of boys, if Amit who is tenth from the right and Bittu who is ninth from the left, interchange their positions, Amit becomes fifteenth from the right. How many boys are there in the row?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 23
After the interchange, Amit stands in Bittu’s old place. That place is 9th from the left (Bittu’s position), and Amit is now 15th from the right, so both positions describe the same boy.
Counting from the left and counting from the right both include this boy, so adding the two positions counts him twice
Number of boys: \(9+15-1=23\)
Tip: Amit’s first position (10th from the right) is not needed here; use the two positions that describe the same place in the row after the change.