Examkin

Question

Difficulty: EasyOrder and Ranking

A local theater has a single continuous row of 42 seats in its front balcony. A guest's assigned seat is the 12th12^{\text{th}} one when counting from the left side. What is the position of this exact same seat when counting from the right side?

  1. A
    30th30^{\text{th}}
  2. B
    12th12^{\text{th}}
  3. 31st31^{\text{st}}Answer
  4. D
    32nd32^{\text{nd}}

Answer

31st31^{\text{st}}
To find the position of an item from one end when its position from the opposite end and the total count are known, we subtract the known position from the total number of items, and then add 1. Using the ranking formula R=T−L+1R = T - L + 1, we get 42−12+1=3142 - 12 + 1 = 31. Thus, the seat is 31st31^{\text{st}} from the right.

Step-by-Step Solution

1
Identify the total number of seats and the known position from the left.
Total=42Total = 42, Left=12Left = 12
These are the given values required to find the relative position from the opposite end of the row.
2
Apply the standard ranking formula to calculate the position from the right side.
Right=Total−Left+1Right = Total - Left + 1
When converting a rank from one end to the other, subtracting the known rank from the total excludes the item itself from the count, so we must add 1 back to include it.
3
Perform the mathematical calculation.
Right=42−12+1=30+1=31Right = 42 - 12 + 1 = 30 + 1 = 31
Completing the arithmetic yields the final rank from the right side.

Key Concept

Position Calculation from Opposite Ends in a Linear Sequence
Rate this question

Topics

Order and Ranking

More questions from this topic