- #1
member 587159
Homework Statement
I have 3 yellow and 7 blue marbles. I put those randomly in a line. What is the probability that no yellow marbles are next to each other?
Homework Equations
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The Attempt at a Solution
Total amount of opportunities to put those marbles next to each other: 120
Total amount of opportunities to put 3 marbles next to each other: 8
Total amount of opportunities to put 2 marbles next to each other:
(9 nCr 1)*(8 nCr 1) = 72
72 - (8 nCr 1) = 64
1 - (64+8)/120 = 2/5
Can someone verify whether I'm correct? Or at least tell me where I am wrong?