Answer : The number of marbles lined up across the circumference of the earth can be, [tex]8.013\times 10^{10}[/tex] marbles
Explanation :
First we have to calculate the diameter of tiny marble.
[tex]Diameter=2\times Radius[/tex]
r = radius of marble = 0.25 mm
[tex]Diameter=2\times (0.25mm)=0.50mm[/tex]
Now we have to calculate the number of marbles can be lined up across the circumference of the earth.
Given:
Circumference of the earth distance = [tex]24900mile=4.00641\times 10^{10}mm[/tex]
conversion used: [tex]1mile=1.609\times 10^6mm[/tex]
Number of marbles can be lined up = [tex]\frac{4.00641\times 10^{10}mm}{0.50mm}=8.013\times 10^{10}[/tex] marbles
Thus, the number of marbles lined up across the circumference of the earth can be, [tex]8.013\times 10^{10}[/tex] marbles