First one hope this helps!
Answer: 
Step-by-step explanation:
Here, According to the question, The population of the world is 4 billion (approx).
Again According to the question, The world's population has grown at an average rate of 1.9 percent per year since 1945.
Therefore, after 1975 the growth rate will remains same.
Thus, the population of the world after t years,
(By the formula
)
⇒
Where 1.019 is the growth rate and 4 billion is the initial population.
461 because you take 506-45 to find x(the unknown number)
Maybe u should study i know its hard but try ur best :)
We know that
the axis is equal to the diameter of a sphere
so
D=14 units
r=D/2-----> r=7 units
<span>the surface area of the sphere=4*pi*r</span>²------> 4*pi*7²=196*pi units²
the answer is the option
<span>C. 196 pi units^2</span>