Why are countries such a Africa and Asia,so rich in minerals,but people there are starving everyday?

For one thing, neither Africa nor Asia is a country. They are continents composed of many countries, each country looking out for Number One. In most countries, the mining rights are owned by private interests not the governments, and many such interests were established long ago by other nations' empirical policies (The British Empire, for example). Economic profit from such mining does not always stay in that country but is transferred to the mining companies' country of origin or at least to that company. The mining/drilling money that stays in the country is usually in the form of workers wages and taxes, a small percentage of the total wealth. Even in those countries where the governments run the mining/drilling, many of the governments are corrupt and the money goes into the pockets of the leaders, and much the same can be said for the kingdom countries. Factor that in with the many civil wars and natural disasters that these countries are ill-prepared for and it's the common people who suffer.