A Multiplication Based Logic Puzzle

492 is the sum of some consecutive prime numbers (actually two different ways: see the comments). I’ll list those primes in the comments in about a week unless somebody else beats me to it. (abyssbrain beat me to it.)

Simplifying the square root of 492 is as easy as 1-2-3:

92 can be evenly divided by 4, so 492 is also divisible by 4. If I wanted to find √492, I would make a little cake and divide 492 by 4.

492 cake

123 is not divisible by 4 or by 9, but it is divisible by 3 so I will do that division next and get a quotient of 41, a prime number. Now I will take the square root of everything on the outside of the cake and multiply them together: √492 = (√4)(√3)√(41) = (√4)(√123) =2√123

492 Puzzle

Print the puzzles or type the solution on this excel file: 10 Factors 2015-05-11

—————————————————————————————————

  • 492 is a composite number.
  • Prime factorization: 492 = 2 x 2 x 3 x 41, which can be written 492 = (2^2) x 3 x 41
  • The exponents in the prime factorization are 2, 1, and 1. Adding one to each and multiplying we get (2 + 1)(1 + 1)(1 + 1) = 3 x 2 x 2 = 12. Therefore 492 has exactly 12 factors.
  • Factors of 492: 1, 2, 3, 4, 6, 12, 41, 82, 123, 164, 246, 492
  • Factor pairs: 492 = 1 x 492, 2 x 246, 3 x 164, 4 x 123, 6 x 82, or 12 x 41
  • Taking the factor pair with the largest square number factor, we get √492 = (√4)(√123) = 2√123 ≈ 22.181073

—————————————————————————————————

492 Logic

Advertisements

Comments on: "Simplifying √492 and Level 5" (2)

  1. abyssbrain said:

    Ha! I found two solutions 🙂 First, I quickly found that it’s the sum of two consecutive primes.

    241 + 251 = 492

    But I knew that it’s not that easy, so I tried to find another solution, and here it is,

    492 = 71 + 73 + 79 + 83 + 89 + 97

    Liked by 1 person

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Tag Cloud