2025 AMC 8

Complete problem set with solutions and individual problem pages

Problem 13 Medium

Each of the even numbers 2, 4, 6, \ldots, 50 is divided by 7. The remainders are recorded. Which histogram displays the number of times each remainder occurs?

  • A.

  • B.

  • C.

  • D.

  • E.

Answer:A

Solution 1

Let's take the numbers 2 through 14 (evens). The remainders will be 2, 4, 6, 1, 3, 5, and 0. This sequence keeps repeating itself over and over. We can take floor(50/14) = 3, so after the number 42, every remainder has been achieved 3 times. However, since 44, 46, 48, and 50 are left, the remainders of those will be 2, 4, 6, and 1 respectively. The only histogram in which those 4 numbers are set at 4 is histogram \boxed{\textbf{(A)}}.

 

Solution 2

Writing down all the remainders gives us

2, 4, 6, 1, 3, 5, 0, 2, 4, 6, 1, 3, 5, 0, 2, 4, 6, 1, 3, 5, 0, 2, 4, 6, 1.

In this list, there are 3 numbers with remainder 0, 4 numbers with remainder 1, 4 numbers with remainder 2, 3 numbers with remainder 3, 4 numbers with remainder 4, 3 numbers with remainder 5, and 4 numbers with remainder 6. Manually computation of every single term can be avoided by recognizing the pattern alternates from 0, 2, 4, 6 to 1, 3, 5 and there are 25 terms. The only histogram that matches this is \boxed{\textbf{(A)}}.