2024 AMC 8

Complete problem set with solutions and individual problem pages

Problem 5 Easy

Aaliyah rolls two standard 6-sided dice. She notices that the product of the two numbers rolled is a multiple of 6. Which of the following integers cannot be the sum of the two numbers?

  • A.

    5

  • B.

    6

  • C.

    7

  • D.

    8

  • E.

    9

Answer:B

Solution 1

First, figure out all pairs of numbers whose product is 6. Then, using the process of elimination, we can find the following:

\textbf{(A)} is possible: 2\times 3

\textbf{(C)} is possible: 1\times 6

\textbf{(D)} is possible: 2\times 6

The only integer that cannot be the sum is \boxed{\textbf{(B) } 6}.

 

Solution 2

First, see that in order for the two numbers to have a product of 6, it must either have 6 as a factor or have factors that have a product of 6 (Notably 2\times 3).

When we look at the answer choices, we see that answers C, D, E all are more than 6, so they can all be added as a sum of 6. Answer A works because 2+3=5, so 6 is the only answer choice that doesn't work. Thus, the answer is \boxed{\textbf{(B) } 6}.