Intelligent Math Puzzle – Challenge 81
Intelligent Math Puzzle - Challenge 81 is a multiple-choice math challenge from Effortless Math. Read the problem, choose from the answer options below, then open the solution to see the full step-by-step working and check your reasoning against it.
Enjoy solving math puzzles and critical thinking challenges? If so, then this challenge is just for you. The answer is also given.
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
Related to This Article
More math articles
- Connecticut Grade 2 English Worksheets You Can Print Free
- 7th Grade PSSA Math Worksheets: 68 Free PDFs by Topic
- Senate confirmation
- How Can You Use Math for Calculating Your Winning?
- How to Solve the Converse of Pythagoras’ Theorem Problems?
- The Best Grade 4 Math Book for New York Students
- What Is a Good ALEKS Score?
- ParaPro Math Formulas
- How to Interpret Pie Graphs? (+FREE Worksheet!)
- 7th Grade English Worksheets for New York (NYS ELA): 43 Free Printable PDFs
What people say about "Intelligent Math Puzzle: Challenge 81"?
No one replied yet.