SOLUTION: If there are 6 red disks numbered 1 through 6, and 8 yellow disks numbered 7 through 14, find the probability of selecting a red disk, given that an odd-numbered disk is selected.

Algebra ->  Probability-and-statistics -> SOLUTION: If there are 6 red disks numbered 1 through 6, and 8 yellow disks numbered 7 through 14, find the probability of selecting a red disk, given that an odd-numbered disk is selected.       Log On


   

Question 960264: If there are 6 red disks numbered 1 through 6, and 8 yellow disks numbered 7 through 14, find the probability of selecting a red disk, given that an odd-numbered disk is selected.
A) 4/7
B) 3/14
C) 2/7
D) 3/7
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
First draw out the disks and color each one



We are told that "an odd-numbered disk is selected" since it is given to be true. In other words, it is guaranteed to happen or this bit of information is fully known.

So what we do is highlight the disks that have odd numbers on them. I'm going to place them in boxes.


Then erase the ones that weren't placed in boxes. This is to avoid dealing with the disks we know that we haven't selected (remember: we are told or we know 100% that we selected an odd number disk)



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It asks: "find the probability of selecting a red disk"

There are 7 disks left over in the boxes that are odd. There are 3 red disks that are left over.

So the probability of picking a red disk from this leftover group is 3/7

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Final Answer: 3/7

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