Question

It is estimated that light takes 110,000 years to travel the full distance across our galaxy

Answer 1

$\bf \stackrel{light~speed}{3.0\times 10^8}ms^{-1}\implies \stackrel{light~speed}{3.0\times 10^8}~\frac{m}{s}\implies 300,000,000~\frac{m}{s}\\\\ -------------------------------\\\\ \textit{how many seconds in a minute?}\qquad 60 \\\\\\ \textit{how many seconds in }\stackrel{1~hr}{60~minutes?}\qquad 60\cdot 60 \\\\\\ \textit{how many seconds in }\stackrel{1~day}{24~hrs}?\qquad 60\cdot 60\cdot 24 \\\\\\ \textit{how many seconds in }\stackrel{1~year}{365~days}?\qquad 60\cdot 60\cdot 24\cdot 365$

now, it takes 1 second for light to travel 300,000,000 meters.

if we know it takes light 1 second to go 300 million meters, then in 365 days or a year, or 60*60*24*365 seconds, it will then travels

300,000,000 * 60 * 60 * 24 * 365 meters in 1 year,

how about in 110,000 years, how many meters has it travelled?

300,000,000 * 60 * 60 * 24 * 365 * 110,000   that many meters.

we know she travels the Milky Way in 110,000 years  or 60 * 60 * 24 * 365 * 110,000  seconds

and we know that 110,000 years is 3468960000000 seconds, so

if it travels 300000000 meters in only 1 second, in 3468960000000 seconds, it will travel then (300000000) * (3468960000000) meters

or  1040688000000000000000 meters.