anonymous 3 years ago Thomas hardy has to sketch a side of a plain white paper. There are 8 parallel lines which divides the paper into nin3 equal areas. Each section of area needs an entire crayon to color it up. He has five magenta,five cyan and five green crayons. He is allowed to use a maximum of two colors. How many different ways can he sketch the paper?

1. anonymous

2. anonymous

help me please as soon as possible

3. anonymous

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4. anonymous

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5. anonymous

help me pls

6. anonymous

use the formula to find combinations : $nCr= \frac{ n! }{ r! (n-r)! }$ where n = the number you are choosing from (total number of crayons) r= the number you have to choose the (!) means factorials so for example 4! is 4x3x2x1

7. anonymous

how to determine r???

8. anonymous

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9. anonymous

well r will be 2 the problem tells you

10. anonymous

yea i tried that bt thats not the answer

11. anonymous

you will be able to determine the number of ways the colors can be used in pairs. after you determine that now use that as the total number (n) and r =9 since its 9 different areas

12. anonymous

ohh

13. anonymous

then is it 25C9 ???

14. anonymous

2042975

15. anonymous

its 15 colors and you choose 2 , therefore 15C2= 105 that gives you how many ways you can use those 15 colors in pairs. but the problem is asking you how many ways you can use all those colors to color 9 areas

16. anonymous

now how many ways can you use those 9 areas with the two colors 9C2= 36

17. anonymous

wat abt that 8 parallel lines