## anonymous one year ago The figure below shows a shaded circular region inside a larger circle: A shaded circle is shown inside another larger circle. The radius of the smaller circle is labeled as r and the radius of the larger circle is labeled as R. On the right side of the image is written r equal to 3 inches and below r equal to 3 inches is written R equal to 5 inches. What is the probability that a point chosen inside the larger circle is not in the shaded region? 24% 36% 50% 64%

1. anonymous

@Jamierox4ev3r

2. anonymous

@Jamierox4ev3r

3. anonymous

4. Jamierox4ev3r

shoot I'm not sure about the whole probability thing x'D

5. Jamierox4ev3r

but you could solve for area. and then make those ratios

6. anonymous

@iGreen

7. anonymous

@whpalmer4

8. anonymous

@iGreen

9. Jamierox4ev3r

oh wait nvm i remember x'D lol sorry

10. anonymous

ok

11. Jamierox4ev3r

so yeah. find area. the formula is $$\pi r^{2}$$

12. Jamierox4ev3r

let's start with the smaller circle: $$A=\pi r^{2}$$ A=$$\pi 3^{2}$$

13. Jamierox4ev3r

so multiply pi by 2.... what do you get? @Marc1313

14. anonymous

3.14 by 2?

15. anonymous

6.28

16. Jamierox4ev3r

i meant by 9..lol sorry xD since $$3^[2]$$ is 9

17. anonymous

28.26

18. Jamierox4ev3r

**$$3^{2}$$

19. Jamierox4ev3r

yep. so that's the area of the smaller circle

20. Jamierox4ev3r

can you find me the area of the larger circle?

21. anonymous

how

22. anonymous

this is confusing

23. Jamierox4ev3r

just do it with this formula i used earlier $$A=\pi r^{2}$$ $$A=pi 5^{2}$$ which becomes $$A=\pi 25$$

24. Jamierox4ev3r

multiply pi by 25 to find the area of the larger circle

25. Jamierox4ev3r

@Marc1313 can you multiply pi by 25 to find the area of the larger circle?

26. anonymous

85

27. anonymous

@Jamierox4ev3r

28. Jamierox4ev3r

actually, 78.54

29. Jamierox4ev3r

but close :)

30. Jamierox4ev3r

there's one final step to find the answer...set the areas as a ratio, like so: $$\Large\frac{28.27}{78.54}$$ ^^ then simplify it :)

31. anonymous

78.5

32. anonymous

36%

33. Jamierox4ev3r

yep :) make sense?

34. anonymous

a little

35. anonymous

are you sure that si the answer

36. Jamierox4ev3r

cool. basically, find the areas, and then make a ratio (fancy way of saying division) :)

37. Jamierox4ev3r

positive. I remember this unit now, lol i realized that it wasn't probability, it was just ratios :P

38. anonymous

Thank you so much next question