Africa have a population of roughly 1.3 billion people. If we use basic arithmetic, we can analyzing the following.
We assume that Africa needs 20 trillion dollar for its development.
If 1 billion Africans contribute 1 dollar per month, we make 10 billion dollar in 10 month.
If 1 billion Africans contibute 10 dollar per month, we make 100 billion dollar in 10 month.
If 1 billion Africans contribute 100 dollar per month, we make 1 trillion dollar in 10 month.
If 1 billion Africans contribute 1000 dollar per month, we make 1 trillion dollar
in 1 month and 10 trillion dollar in 10 month.
Since it is difficult for majority of Africans to contribute 1000 dollar per month, let us brake it
in every 10 month, which means 1 billion Africans contribute 1000 dollar per 10 month.
First 10th month, we have 1 trillion dollar. Second 10th month, we have 1 trillion dollar.
It will thus cost us 100 month (10th 10th month) to make 10 trillion dollar.
Which means 200 month to make 20 trillion dollar.
Let us say 1 year = 10 month
This means we need 200 month/ 10 month = 20 years to develop Africa.
Since more than 300 000 years Africa is still searching for development.