220k views
1 vote
Probability of landing in the white not the red. Please helpppppppppppp!

Probability of landing in the white not the red. Please helpppppppppppp!-example-1

1 Answer

3 votes

Fun, geometry disguised as probability.

That's a pentagon, which we can view as 10 right triangles with legs a and s/2 (half of s) and hypotenuse r. So area of the pentagon is

P = 10 × (1/2) a (s/2) = 10 (1/2) (3.2) (4.7/2) = 37.6

The area of the circle is πr² so the circle area is

C = π (4²) = 50.265482

The white area is the difference, C-P, and the probability we seek is the fraction of the circle that's white, so (C-P)/C.

p = (C-P)/C =1-P/C = 1-37.6/50.265482 = 0.251971

Answer: 0.25

Higher than I would have guessed from the figure.

User Tapy
by
8.4k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories