Intelligent Math Puzzle – Challenge 81
Enjoy solving math puzzles and critical thinking challenges? If so, then this challenge is just for you. The answer is also given.
[include_netrun_products_block from-products="product/ssat-middle-level-math-for-beginners/" product-list-class="bundle-products float-left" product-item-class="float-left" product-item-image-container-class="p-0 float-left" product-item-image-container-size="col-2" product-item-image-container-custom-style="" product-item-container-size="" product-item-add-to-cart-class="btn-accent btn-purchase-ajax" product-item-button-custom-url="{url}/?ajax-add-to-cart={id}" product-item-button-custom-url-if-not-salable="{productUrl} product-item-container-class="" product-item-element-order="image,title,purchase,price" product-item-title-size="" product-item-title-wrapper-size="col-10" product-item-title-tag="h3" product-item-title-class="mt-0" product-item-title-wrapper-class="float-left pr-0" product-item-price-size="" product-item-purchase-size="" product-item-purchase-wrapper-size="" product-item-price-wrapper-class="pr-0 float-left" product-item-price-wrapper-size="col-10" product-item-read-more-text="" product-item-add-to-cart-text="" product-item-add-to-cart-custom-attribute="title='Purchase this book with single click'" product-item-thumbnail-size="290-380" show-details="false" show-excerpt="false" paginate="false" lazy-load="true"]
Challenge:
What is the last number in the 18th row in the following pattern?
First row: 2
Second row: 3 4
Third row: 5 6 7
Fourth row: 8 9 10 11
…
A- 169
B- 170
C- 171
D- 172
E- 173
The Absolute Best Book to Challenge Your Smart Student!
The correct answer is D.
Each row has one number more than the previous row. The first row has one number, the second row has two numbers, and the 18th row has 18 numbers.
To answer the question, we should find the number of numbers in all 18 rows.
\(1 + 2 + 3 + … + 17 + 18 = \frac{18}{2}(1+18) = 171\)
The first number starts with 2. Therefore, the last number is 172 (171 +1).The Best Books to Ace Algebra
Original price was: $27.99.$17.99Current price is: $17.99.
Related to This Article
More math articles
- 7th Grade WVGSA Math Worksheets: FREE & Printable
- Discover the Gateway: “CBEST Math for Beginners” Full Solution Handbook
- 10 Most Common 7th Grade FSA Math Questions
- How to Divide Mixed Numbers? (+FREE Worksheet!)
- TABE Math Formulas
- How to Interpret Pie Graphs? (+FREE Worksheet!)
- How to Use Measures of Center and Spread to Compare Populations
- The Ultimate 6th Grade LEAP Math Course (+FREE Worksheets)
- 3rd Grade Georgia Milestones Assessment System Math Worksheets: FREE & Printable
- Function Values of Special Angles

















What people say about "Intelligent Math Puzzle – Challenge 81 - Effortless Math: We Help Students Learn to LOVE Mathematics"?
No one replied yet.