Answer:
A high plateau encircled by mountains are called altiplanos
Explanation:
Set this up as
10 = 40 (1/2)t/28
and solve for t in years.
10/40 = (1/2)t/28
log(0.25) = (t/28) log(0.5)
t = 28 log(0.25) / log(0.5) years = 56 years
Test the answer:
56 years = 2(28 years) = 2 half-lives, so the remaining amount should be 1/2 of 1/2 of the initial amount, i.e. 1/4 of the initial amount, and 10 mg = 1/4 of 40 mg.
According to research, Brazil, Argentina, and Columbia all have the highest GNP.
I know for sure the ganga and brahmaputra rivers do make up the northern plains, not sure about the yamuna. but since two do, then i would answer all of these
