Question

Tara is researching the stork population living in a bird reserve. On her first day, she captures and tags 41 birds. Two weeks later, she captures 57 birds and finds 48 are not tagged. Estimate the actual number of storks in the bird reserve

Answer 1

Hmm, we will do ratio and assume caputred is in proprtion

so

all:tagged=all:41
we will assume this is the same as
57:tagged in the 57
57-41=16 so 16 are not tagged

so
all/41=57/16
times both sides by 41
all=2337/16
all=146.something
about 146 storks

Answer 2

Answer:

There were approx 260 storks in the bird reserve.

Step-by-step explanation:

We are given a information as:

Tara is researching the stork population living in a bird reserve.

• On her first day, she captures and tags 41 birds.

Let there were total 'x' birds.

Then the probability of the tagged birds is: $\dfrac{41}{x}$

• Two weeks later, she captures 57 birds and finds 48 are not tagged.

 number of birds  tagged=57-48=9.

Now the probability of tagged birds is: $\dfrac{9}{57}$

As the probability of the tagged birds must be same:

⇒    $\dfrac{41}{x}=\dfrac{9}{57}$

⇒   $x=\dfrac{41\times 57}{9}$

⇒   $x=259.666$

Hence, there were approx 260 storks  in the bird reserve.