Related ImageBe who you are and say what you feel, because those who mind don't matter and those who matter don't mind. - Dr. Seuss
spc Bd 1 Bd 3
Share This Page

Math Puzzle Answer

You’re looking at the solution to one of our math puzzles. We have several other puzzles for you to solve. Please click to see all our math puzzles.


Math Puzzle Answer

CD Track Lengths - Answer

The lengths of the tracks are (5, 7, 17, 19), (7, 11, 13, 23) and (7, 13, 17, 23).

None of the track lengths can be 2 because any sum of the three different primes, including 2, would not be prime. Therefore, the track lengths must be chosen from the 13 primes between 3 and 43.

To get the answer, find all three prime combinations whose sum is a small enough prime that another prime (larger than any of the three) can be added to result in a sum of 60 or less.

There are 14 such combinations: (3, 5, 11), (3, 5, 23), (3, 7, 13), (3, 7, 19), (3, 11, 17), (5, 7, 11), (5, 7, 19), (5, 11, 13), (5, 13, 19), (7, 11, 13), (7, 11, 19), (7, 13, 19), (7, 13, 17) and (11, 13, 17).

If you try all possible fourth primes with those combinations, you'll find that the only possibilities which meet the requirements (sum of 60 or less and sum of any three is a prime) are the answers given above.

Home Brain Teasers Cryptic Math Puzzles Logic Puzzles Math Puzzles Hard Math Puzzles Word Picture Puzzles

Logic Games

Play Mastermind Same Game Play ShisenSho

Other Games

Car Games Skiing Games Football Games Free Kid Puzzles Magic Triangle Game
US Jokes Hilarious Blonde Jokes I have Learned...
Play Javaroids Kid Games Play Black Viper FastLap Dublin Driving Game Wermz Online Game Classic Online Games
Stereogram Pictures Weird Illusions Visual Illusions

Optical Illusions

We have free optical illusions, funny illusions, Muller-Lyer illusion, tricks and illusions and more.
Get the Explanation
for this
Optical Illusion
Our Site Map Some Related Links Link To Us Send This To A Friend Comments/Suggestions
Report A Broken Link Contact Information


Site Map | Terms of Use | Privacy & Security | Contact Us | Purchase Agreement | Send Feedback
Brain Teasers, Logic Puzzles, and other Fun Brain Activities
© 1996-2005 by All Rights Reserved.