Rabbit litter Problems

This is an old question. Today, I suddenly remembered it.

Problem description:

There was a rabbit. Since the first 3rd months after birth, a rabbit was born every month. After the third month, a rabbit was born every month. If the Rabbit does not die, what is the total number of rabbits in a month?

 

Analysis can be displayed in a table.

 

 

Immature	Mature	Total	Month
1	0	1	1
0	1	1	2
1	1	2	3
1	2	3	4
2	3	5	5

 

The following table is skipped !! Ignore it.

Immature	Mature	Total
1	0	1
0	1	1
1	1	2
1	2	3
2	3	5

 

 

 

A pair of rabbits were immature in January. The second month has become mature.

In March, their baby was born.

So proceed .... It is the Fibonacci series.