Which points are on graph of f(x)=2(0.5)^x

Since no points are given, you can make your own points.
Put x=0, then f(x)=2(0.5)^0=2*1=2  => (0,2)
Put x=1, then f(x)=2(0.5)^1=2(0.5)=1  => (1,1)
Put x=2, then f(x)=2(0.5)^2=2(1/4)=1/2 => (2, 1/2)

The answer for this question is 80