SOLUTION: Rework problem 9 from section 2.3 of your text. Assume that you have 6 dimes and 5 quarters (all distinct), and you select 4 coins. (1) In how many ways can the selection be ma

Algebra ->  Probability-and-statistics -> SOLUTION: Rework problem 9 from section 2.3 of your text. Assume that you have 6 dimes and 5 quarters (all distinct), and you select 4 coins. (1) In how many ways can the selection be ma      Log On


   



Question 646779: Rework problem 9 from section 2.3 of your text. Assume that you have 6 dimes and 5 quarters (all distinct), and you select 4 coins.
(1) In how many ways can the selection be made? 330
(2) In how many ways can the selection be made if all the coins are dimes? 15
(3) In how many ways can the selection be made if you select 2 dimes and 2 quarters? 150
(4) In how many ways can the selection be made so that at least 2 coins are dimes?
I'm confused on number four. I tied using 6c2+6c3+6c4 and multiplying the same set but none of the answers are right. I know the problem can be set up as total-less than two options but i dont know how to set up the permutiation or combination. I do understand how to visualize the problem though

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 
Hi,
6 dimes and 5 quarters (all distinct), and you select 4 coins
(1) In how many ways can the selection be made? 11C4 = 330 Yes.
(2) In how many ways can the selection be made if all the coins are dimes? 6C4 = 15 Yes.
(3) In how many ways can the selection be made if you select 2 dimes and 2 quarters? 6C2%2A5C2%29 = 150 Yes.
(4) In how many ways can the selection be made so that at least 2 coins are dimes?
330-+5C4+-+5C3%2A6C1+=+330+-5+-+10%2A6+=+300-65+=+235