Question

A fish bowl contains blue, green and red plastic fish. When a fish is picked out at random, the probability of it being blue is 0.7 and the probability of it being green is 0.2. A prize is given if a red fish is picked out. What is the probability of Matt picking a red fish? (Give your answer as a decimal.) There are 60 fish in the fish bowl. How many of the fish are red?

Answer 1

Answer:

0.1 probability of Matt picking a red fish

6 of the fish are red.

Step-by-step explanation:

We have these following probabilities:

70% = 0.7 probability that the fish is blue.

20% = 0.2 probability that the fish is green.

p probability that the fish is red.

The sum of all these probabilities is 100% = 1. So

0.7 + 0.2 + p = 1.

p = 0.1

0.1 probability of Matt picking a red fish

There are 60 fish in the fish bowl. How many of the fish are red?

n trials with p probability of sucess. The expected value is

$E(X) = np$

Here we have $n = 60, p = 0.1$. So

$E(X) = np = 60*0.1 = 6$

6 of the fish are red.