Other Topics Puzzle – Challenge 98
Time to challenge and tease your brain with another great math puzzle. Let's see if you can solve it. The solution is also provided.
Challenge:
In how many ways can Ann, Bea, Cam, Don, Ella and Fey be seated on a straight line if Ann and Bea cannot be seated next to each other?
A- 240
B- 360
C- 480
D- 620
E- 720
The Absolute Best Book to Challenge Your Smart Student!
The correct answer is C.
The formula for N people to sit in a straight line is N! and at a round table there is (n-1)!.
There are six people. So, the number of different ways to sit them is 6! = 720
From these 720 ways, we must subtract the number of ways that Ann and Bea can sit next to each other.
The cases we need to subtract from whole are the ways of seating 5 persons and one “pair”. That would be 5! or 5 × 4 × 3 × 2 × 1 = 120
However, there are two ways Ann and Bea could sit, Ann left of Bea or Bea left of Ann.
So, we double 120 ways to 240 ways.
Answer: 720 – 240 = 480
The Best Books to Ace Algebra
Related to This Article
More math articles
- How to Solve Radicals? (+FREE Worksheet!)
- How to Piece Together Areas: Compound Figures with Triangles, Semicircles, and Quarter Circles
- 7th Grade ACT Aspire Math Worksheets: FREE & Printable
- Top 10 4th Grade PSSA Math Practice Questions
- How to Prepare for the SSAT Middle-Level Math Test?
- How to Convey Decimals in Words
- Integrals: Everything You Need To Know
- Full-Length CLEP College Algebra Practice Test-Answers and Explanations
- 6th Grade OSTP Math Worksheets: FREE & Printable
- Hоw to Gеt a Great Sсоrе оn thе SAT Math Test
What people say about "Other Topics Puzzle – Challenge 98 - Effortless Math: We Help Students Learn to LOVE Mathematics"?
No one replied yet.