Question

Roselin had an aquarium at her home with 10 fish in it. In a year, a fish gave birth to 7 fish. During this period, 3 adult fish had died. Roselin's father purchased 2 more pairs of fish from market for the aquarium. Later, Roselin gifted 4 fish from the aquarium to her friend. Find out the growth rate of fish in Roselin's aquarium.

Hint:

Growth rate calculation must include both internal (birth/death) and external (immigration/emigration) factors if provided.

Answer 1

Step 1: Write the initial population.
Initially, the number of fish in the aquarium = 10.

Step 2: Add the fish born during the year.
A fish gave birth to 7 fish.
Total fish after birth:
\(10 + 7 = 17\).

Step 3: Subtract the fish that died.
During the year, 3 adult fish died.
Remaining fish:
\(17 - 3 = 14\).

Step 4: Add the fish purchased from the market.
Roselin’s father bought 2 pairs of fish.
1 pair = 2 fish
So, 2 pairs = 4 fish.
Total fish now:
\(14 + 4 = 18\).

Step 5: Subtract the fish gifted to her friend.
Roselin gifted 4 fish.
Final population:
\(18 - 4 = 14\).

Step 6: Calculate the growth rate.
Growth rate = Final population − Initial population
\[ 14 - 10 = 4 \]
Thus, the population increased by 4 fish.

Final Answer:
The growth rate of fish in the aquarium is 4 fish per year.