Question

A certain star is 1.7 x 102 light years from the Earth. One light year is about 5.9 x 1012 miles. How far from the earth (in miles) is the star?

Answer 1

The star is 1.7 * 10^2 light years from the earth. Given that one light year is about 5.9 * 10^12 miles, then the distance of the star from the earth is

`\begin{gathered} 1.7\text{ }*10^2*5.9*10^(12) \\ =\text{ }10.03\text{ }*10^(2+12) \\ =10.03*10^(14) \\ =\text{ 1.003 }*10^(15)\text{ miles} \end{gathered}`