Help me with this geometry question, please?
And show your work?
D: I need to understand this.
Thank you!
3. Answer the questions below based on the target pictured. You may assume the dart hits the target every time. Hint: Leave your solutions in terms of pi; do not multiply by 3.14. Simply write “pi” for the pi symbol.
A target is drawn with 4 concentric circles. The innermost circle is red with a radius of 2, the yellow ring has a radius of 3 more than the red, the blue ring has a radius of 3 more than the yellow and the green has a radius of 3 more than the blue.
Image: http://i21.tinypic.com/11v07bo.gif
Part a) Find the geometric probability of throwing a dart and hitting the red circle.
Part b) Find the geometric probability of throwing a dart and hitting the blue or green rings.
Part c) Find the geometric probability of throwing a dart and hitting the yellow ring using your answers for parts a and b.
2007-10-27 08:02:56 · 1 answers · asked by eirhya 1 in Education & Reference ➔ Homework Help
For this, you need to find the areas of each of the regions to find probablility. Probability in general is the odds of getting something divided by the entire something (i.e. getting a blue block out of 6 different colored blocks is 1/6). The area of the whole thing is pi*r^2, or 121pi. This will be our denominator for everything.
For the first one, the area of the red circle is pi*r^2, or 4pi. Thus, the probablility of hitting it is 4pi/121pi, or 4/121.
The area of the blue and green rings is found by taking the area of the entire board and subtracting the red and yellow areas. The area of the entire thing is 121pi, and the area of the yellow area (which includes the red area as well) is 25pi. Thus, the area of the green and blue areas is 121pi - 25pi, or 96pi, and the probability of hitting the green or blue areas is 96pi/121pi, or 96/121.
Finally, finding the yellow area is found by taking the entire target, 121pi, and subtracting out the green/blue, 96pi, and the red, 4pi. This gives us 21pi, and the odds of hitting the yellow area is 21pi/121pi, or 21/121.
2007-10-29 07:48:24 · answer #1 · answered by igorotboy 7 · 0⤊ 0⤋