Answer:
680
Step-by-step explanation:
Number of red beans = 30
Number of Blue beans = 30
Number of green beans = 30
How many color combinations of 15 beans have at least 6 green beans?
Since at least 6 of the beans must be green,
Then (15 - 6) = 9
Then, the remaining 9 could be either red, blue or green.
Therefore, C(9 + (9 - 1), 3)
C(17, 3) = 17C3
nCr = n! ÷ (n-r)! r!
17C3 = 17! ÷ (17 - 3)! 3!
17C3 = 17! ÷ 14!3!
17C3 = (17 * 16 * 15) / (3 * 2)
17C3 = 4080 / 6
17C3 = 680 ways
