Probability question help (1 Viewer)

[plutonium-238]

Can someone please help me with this question:

The chance of a fisherman catching a legal length fish is 4 in 5. If three fish are caught at random, what is the probability that exactly one is of legal length?

Thanks!!

 

[bokat]

Since the chance of catching a legal length is 4/5, the chance of not catching one is 1/5.
Since we talk about 3 catches then:
4/5x1/5x1/5=4/125 is the chance of 1st catch only being a legal length
1/5x4/5x1/5=4/125 is the chance of 2nd catch only being a legal length
1/5x1/5x4/5=4/125 is the chance of 3rd catch only being a legal length
Since all these scenarios are acceptable, the chance of exactly on legal length
is the sum of all which is 12/125.

Reza Bokat
www.cambridgecoaching.com.au

 

[Carrotsticks]

You don't need to calculate it three times.

Since there is no distinction between the fish, we can just find the probability for one case and then multiply by three, since all the other cases will be exactly the same.

 

[bokat]

You don't need to calculate it three times.

Since there is no distinction between the fish, we can just find the probability for one case and then multiply by three, since all the other cases will be exactly the same.

Yes, but we are talking about 2 unit course, not 3 unit or 4 unit. Each course requires its own approach.

Reza Bokat,

www.cambridgecoaching.com.au