Question

sugahead12
Of the 1,000 students in a local college, 420 own brand X mobile phones and 580 own brand Y mobile phones. Of these students, 80 own both brands of mobile phones. Find the probability that a student chosen at random has a brand X mobile phone given that he has a brand Y mobile phone.

A. 2/14

B. 5/21

C. 3/28

D. 4/29

Answer 1

@sugahead12

Answer 2

He dont know

Answer 3

@princeharryyy

Answer 4

@OregonDuck

Answer 5

@dmart180

Answer 6

Have you learned conditional probability?

Answer 7

Its confusing

Answer 8

@Jade3115
Do you know how to draw the Venn diagram of the situation?

Answer 9

To draw the Venn diagram, you subtract 80 (own both) from 420 who own phone X to get 340 students who own ONLY phone x. Similarly for y.

Let
X=event that a student owns phone X, and
Y=event that a student owns phone Y.

So out of the 1000 students, we have 80 who own both, so P(X\(\cap\)Y)=80/1000.
P(Y)=580/1000.
And so
conditional probability that the student owns X given that he owns Y is, by definition of conditional probability
P(X|Y)=P(X\(\cap\)Y)/P(Y)
Since all quantities on the right-hand side are known, the required probability can be calculated.

Answer 10

Thanks so much ! Can you help me with another ?

Answer 11

Definitely, if you participate!

Answer 12

in a factory the chance that a certain machine works without overheating in the morning is 50% . if it runs smoothly all morning then there is an 85% chance that it will continue for the rest of the day and 15% chance that it will stop due to over heating . what is the probability that on a given gay it will work in the morning and overheat later on ?

Answer 13

& my bad I'm doing this Plato thing

Answer 14

Here's a tree diagram that I started. Can you please fill in the probabilities of each branch?

Answer 15

Its 7.5% ?

Answer 16

Did you get that without using the tree diagram?

Answer 17

I did sum extra stuff & it seemed right . & it was correct !! Any idea ab this one ? Two friends, Bob and Ben, each buy one lottery ticket. Each ticket contains six numbers from a total of one hundred numbers (0–99). Bob chooses the numbers 1, 2, 3, 4, 5, 6, and Ben chooses the numbers 39, 45, 66, 72, 74, 89. Who has a higher probability of winning?

Answer 18

What do you think?

Answer 19

I think Ben just not sure

Answer 20

and your reasoning?

Answer 21

Bc his numbers are kinda scattered so he has a better number choices

Answer 22

You know in these lotteries, they use identical physical balls each with a number painted on it. This is to make sure every number has an equal chance of being drawn.
So based on this information, can you reconsider your reasoning?

Answer 23

Not enough information ?

Answer 24

Noo both have equal chances right ?

Answer 25

Yes it was lol thank you