Question

The world population is projected to be 6.7 billion in 2040. At that​ time, there are expected to be approximately 2 billion more people in Asia than in Africa. The population for the rest of the world will be approximately 0.2 billion more than half the population of Asia. Find the projected populations of​ Asia, Africa, and the rest of the world in 2040.

Answer 1

$\bf \begin{cases} s=\textit{Asia's population}\\ a=\textit{Africa's population}\\ r=\textit{rest of the world}\\ ----------\\ \boxed{s}=a+2\\ \boxed{r}=\frac{s}{2}+0.2 \end{cases}\implies \begin{array}{llll} s+a+r=6.7\\\\ \boxed{a+2}+a+\boxed{\cfrac{s}{2}+0.2}=6.7\\\\ a+2+a+\cfrac{\boxed{a+2}}{2}+0.2=6.7 \end{array}$

solve for "a", to see what Africa's population will then be