Question

what is the approx. difference in RBC count of people living in high altitudes and of people living in the plains?

Answer 1

In high altitude the atmospheric concentration is low as well as the amount of available oxygen in the surrounding is also low. To increase the uptake of as much oxygen as possible our body manufactures more number of RBCs than usual. Thus the people living in high altitude has higher amount of RBCs than in the plain.