Math Problem Statement

Prove that the product of three consecutive even numbers is a multiple of 24

Solution

To prove that the product of three consecutive even numbers is always a multiple of 24, let us break this into logical steps.

1. Representation of Consecutive Even Numbers

Let the three consecutive even numbers be represented as: n,  n+2,  n+4n, \; n+2, \; n+4 where nn is an even integer.

2. Expression for the Product

The product of these three numbers is: P=n(n+2)(n+4)P = n(n+2)(n+4)

3. Multiple of 8

Since nn is even, we can write n=2kn = 2k, where kk is an integer. Substituting n=2kn = 2k into the product: P=(2k)(2k+2)(2k+4)P = (2k)(2k+2)(2k+4) Factor out 2 from each term: P=222k(k+1)(k+2)=8k(k+1)(k+2)P = 2 \cdot 2 \cdot 2 \cdot k(k+1)(k+2) = 8 \cdot k(k+1)(k+2) Thus, PP is always divisible by 88.

4. Multiple of 3

Among kk, k+1k+1, and k+2k+2, one of these numbers is always divisible by 33. This is because any three consecutive integers contain exactly one multiple of 33. Hence, k(k+1)(k+2)k(k+1)(k+2) is divisible by 33.

5. Conclusion: Multiple of 24

Since P=8k(k+1)(k+2)P = 8 \cdot k(k+1)(k+2) is divisible by both 88 and 33, it is divisible by 8×3=248 \times 3 = 24.

Therefore, the product of three consecutive even numbers is always a multiple of 2424.


Would you like further examples or clarifications? Here are some related questions to explore:

  1. Can we extend this proof to three consecutive odd numbers for other divisors?
  2. How would this proof change if we used consecutive integers instead of even numbers?
  3. What are the divisors of the product of four consecutive even numbers?
  4. How can we generalize this proof to nn-consecutive numbers and their product?
  5. Can we use modular arithmetic to prove the divisibility in this case?

Tip: When proving divisibility, always check both prime factors and their powers to verify the result fully!

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Math Problem Analysis

Mathematical Concepts

Number Theory
Divisibility
Arithmetic Sequences

Formulas

Product of three consecutive even numbers: n(n+2)(n+4)

Theorems

Divisibility Rules
Properties of Even Numbers

Suitable Grade Level

Grades 8-10