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 :

There is a 70% probability when the fish is blue

And, 20% probability when the fish is green.

Here we assume p be the probability in the case when the fish is red.

So,

Here the sum of probabilities should be 100% i.e. equal to 1.

The following calculation is to be done

0.7 + 0.2 + p = 1

0.9 + p = 1

So,

p = 0.1

Now for the red one it should be

= 60 (0.1)

= 6

Hence, The probability of Matt at the time of picking a red fish is 0.1.

And, The number of fish that should be red is 6.