2024 AMC 10B Problem 1

Below is the professionally curated solution for Problem 1 of the 2024 AMC 10B, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2024 AMC 10B solutions, or check the answer key.

All of the real AMC 8, AMC 10, AMC 12, and AIME problems in our complete solution collection are used with official legal permission of the Mathematical Association of America (MAA).

Concepts:basic counting

Difficulty rating: 860

1.

In a long line of people, the 10131013th person from the left is also the 10101010th person from the right. How many people are in the line?

20212021

20222022

20232023

20242024

20252025

Solution:

There are 10121012 people to the left of this spot and 10091009 to the right. Add those two groups plus the person themselves: 1012+1009+1=2022.1012 + 1009 + 1 = 2022. Or, just as fast, the two positions overlap on one person, so 1013+10101=2022.1013 + 1010 - 1 = 2022. Thus, B is the correct answer.

Problem 1 in Other Years