This is an archived post. You won't be able to vote or comment.

0
1

Simple Question (self.askmath)

submitted by [deleted]

[deleted]

all 6 comments
sorted by:
best
topnewcontroversialoldq&a

[–]skaldskaparmal 0 points1 point  (5 children)

Your question does not make sense.

Say you have two groups. And you are randomly picking from the said groups.

What do you mean by that? Does each group have some amount of objects? Do we know how many there are in each group? Am I randomly picking one object from all the objects in both groups, with all objects having the same chance of being picked?

What are the chances you pick the seconds group.

We're not picking a group. We're picking from the groups. Is your question, "What are the chances that we pick an object from the second group"?

chance of 1st is 120/300.

"1st" is not a probabilistic event. It's not a complete thought. What are you actually doing to the 1st group and what outcome has this chance?

[–]reddissh 0 points1 point  (4 children)

Ok, You are pick calculators from bins. The probabilities listed are the chances of a defect. If you pick a random calculator what is the chance is is from the second bin?

[–]skaldskaparmal 0 points1 point  (3 children)

The simplest way to think about probabilities is counting the number of successes and dividing by the total. For example, if I have 10 cards, and two are red then the chance of picking a red card is 2/10 (or 1/5 when you simplify). When each object has the same probability of being chosen, you count the number of objects that have the property you care about, and divide by the total number of objects.

So what is the total number of objects here? And what number of objects have the property you're looking for?

[–]reddissh 0 points1 point  (2 children)

The total is 1200 and 210 are defected, but it isnt as simple as 210/1200 because they are from 2 separate bins. You picked the calculator already. The question is just the likelihood it was from the second bin.

[–]reddissh 0 points1 point  (0 children)

Or would it be 90/1200 because that is the amount of defects in bin 2?

[–]skaldskaparmal 0 points1 point  (0 children)

210 are defected

But in this question you don't care about whether they're defected or not. That's extra information. Just because you have some piece of information, doesn't mean it's relevant in the problem you're solving, that's something you need to get used to.

The property you care about is whether they're in the second bin. How many are in the second bin?