Geometry Puzzle – Challenge 69
Who can solve this math puzzle quickly? This is a great logic challenge for those who love critical thinking challenges. Let's challenge your brain!
Challenge:
A length of a rectangle is increased by \(20\%\). What percent of its width should be decreased to keep the area of the rectangle the same?
A- \(15\%\)
B- \(16\frac{2}{3}\%\)
C- \(20\%\)
D- \(25\%\)
E- \(30\%\)
The Absolute Best Book to Challenge Your Smart Student!
The correct answer is B.
The area of a rectangle is the product of its width and length. Let x be the area of the rectangle.
Area of a rectangle = Width × Length = x
Length → 1.2Length → Area of a rectangle = Width × 1.2Length = x
Let W1 be the width of the first rectangle and W2 be the width of the second rectangle.
W1 × 1.2L = W2 × L → W1 × 1.2 = W2 → W1 \(= \frac{1}{1.2}\)W2 →
W1 \(= \frac{5}{6 }\)W2
To keep the area of the rectangle the same \(\frac{1}{6 }\) or \(16\frac{2}{3}\) percent of the width should be decreased.
The Best Books to Ace Algebra
Related to This Article
More math articles
- The Unit Circle
- 10 Most Common 4th Grade PSSA Math Questions
- How to Use Strip Diagrams to Solve Multi-step Word Problems
- 3rd Grade RICAS Math Worksheets: FREE & Printable
- 8th Grade SBAC Math Practice Test Questions
- Getting Better at Math: Realistic Tips and Suggestions
- How to Solve Unknown Angles? (+FREE Worksheet!)
- How to Determine Indeterminate Form and Vague Limits
- Pre-Algebra Formulas
- 10 Most Common CLEP College Algebra Math Questions
What people say about "Geometry Puzzle – Challenge 69 - Effortless Math: We Help Students Learn to LOVE Mathematics"?
No one replied yet.