Answer:

Explanation:
Here, The function that shows the number of butterfly,
or

Where x is the number of years.
4 is the initial number of butterfly,
1 is the annual growth rate.
⇒ If the rate is calculate 5 times in a month,
Then the rate per 5 times a year = 1/5 = 0.2
And, the total number of periods in x years = 5x
Thus, the number of butterfly in x years,

Which is the required formula.