Number Properties Puzzle – Challenge 8
This is a great math challenge about number properties. This math puzzle is a great refresher for those who love mathematics and critical thinking challenges. Let’s challenge your brain!
Challenge:
The number 10 has four different factors: 1, 2, 5, 10. What is the smallest 2 digits number that has exactly three positive factors?
The Absolute Best Book to challenge your Smart Student!
The correct answer is 25.
Each prime number has exactly 2 factors, 1 and the number itself. To find the smallest 2 digits number, n, that has exactly three positive factors, we need to find an odd perfect square number. Why?
The factors of number n are 1, n and a prime number. Let’s consider the smallest prime numbers:
2: If 2 is a factor of n, then n should be 4 (1×2×2). This is not the answer. Since, n should be a 2 digits number.
3: If 3 is a factor of n, then n should be 9 (1×3×3). This is not the answer!
5: If 5 is a factor of n, then n should be 25 (1×5×5). Bingo!The Absolute Best Books to Ace Algebra
Related to This Article
More math articles
- 8th Grade FSA Math Practice Test Questions
- Layout Tools: Square, Level, Plumb, and Straight
- Cell Structure and Function
- How to Find Independent and Dependent Variables in Tables and Graphs?
- The Best Algebra 1 Book for Minnesota Students
- Top 10 Tips to Create a TASC Math Study Plan
- Top 10 HiSET Math Practice Questions
- Right to petition
- How to Solve Equations with Multiple Angles
- Parallel and Perpendicular Lines Worksheet with Answers
What people say about "Number Properties Puzzle – Challenge 8 - Effortless Math"?
No one replied yet.