Probability! (1 Viewer)

[Aysce]

Question:

16. In a group of 25 students, 18 study French, 12 study German and 5 study neither French nor German. If a student is chosen at random, what is the probability that he or she studies:

French or German or both?

 

[nerdasdasd]

hmmm

 

[Shadowdude]

Isn't it... 0.2?

 

[Aysce]

Isn't it... 0.2?

Nope 0.8 or 4/5

 

[nerdasdasd]

THeres 5 extra, thus, 13/25 study french, 7/25 study german, and 5 study both.

 

[D94]

Nope 0.8 or 4/5

Well, it's quite simple: (25-5)/25 = 4/5.

Given 25 people in the class, and given 5 people do not study either F, G or both, then that leaves 20 people who study either F, G or both. Then that's the value over the total amount of students which is 25.

 

[nerdasdasd]

Since the 5 are included in both circles, then its 13/25 + 7/25 = 20/25 = 0.8

 

[Shadowdude]

Isn't it... 0.2?

oops forgot to "1 -" the thing

my bad

 

[Aysce]

Well, it's quite simple: (25-5)/25 = 4/5.

Given 25 people in the class, and given 5 people do not study either F, G or both, then that leaves 20 people who study either F, G or both. Then that's the value over the total amount of students which is 25.

Thanks a lot - yeah I am terrible at probability even at this level but im trying to make it a strength.