## anonymous one year ago A spinner is divided into many sections of equal size. Some sections are red, some are blue, and the remaining are green. The probability of the arrow landing on a section colored red is 9 over 20. The probability of the arrow landing on a section colored blue is 6 over 20. What is the probability of the arrow landing on a green-colored section?

1. jim_thompson5910

hint: all of the probabilities must add to 1

2. anonymous

does anyone understand this

3. anonymous

so what does it mean?

4. jim_thompson5910

x = probability of landing on green $\Large \frac{9}{20}+\frac{6}{20}+x = 1$ are you able to solve for x ?

5. anonymous

no cause i have lots of math to do

6. anonymous

ill try

7. jim_thompson5910

first combine the fractions on the left side

8. jim_thompson5910

tell me what you get

9. anonymous

|dw:1438823076684:dw|

10. jim_thompson5910

good

11. jim_thompson5910

we have this now $\Large \frac{15}{20}+x = 1$

12. jim_thompson5910

subtract 15/20 from both sides $\Large \frac{15}{20}+x = 1$ $\Large \frac{15}{20}+x-\frac{15}{20} = 1-\frac{15}{20}$ $\Large x = 1-\frac{15}{20}$ $\Large x = ???$

13. anonymous

idk

14. jim_thompson5910

try to think of the "1" as "20/20"

15. anonymous

14/20

16. jim_thompson5910

try again

17. jim_thompson5910

$\Large x = 1-\frac{15}{20}$ $\Large x = \frac{20}{20}-\frac{15}{20}$ $\Large x = ??$

18. anonymous

5/20

19. jim_thompson5910

correct, which reduces to 1/4

20. anonymous

21. jim_thompson5910

5/20 is equivalent to 1/4. I just reduced

22. jim_thompson5910

it's always a good idea to reduce fractions as much as possible

23. anonymous

that is nt an answer choice

24. anonymous

@jim_thompson5910

25. jim_thompson5910

what answer choices do they give you?

26. anonymous

The probabilities are equal. The probability of landing on the open end is greater. The probability of landing on the closed end is greater. No conclusion can be made.

27. anonymous

@jim_thompson5910

28. jim_thompson5910

this was for a different problem

29. anonymous

opps let me send the actual chocies

30. anonymous

15 over 20 11 over 20 6 over 20 5 over 20

31. jim_thompson5910

so it looks like they didn't reduce the fraction, which is odd

32. jim_thompson5910

so just don't reduce 5/20

33. anonymous

kk