Question 287641
Set up a proportion:

let t = number of seconds it takes to travel 24000 miles

{{{t/24000 = 15/30}}}

{{{t=12000  seconds}}}

Convert to minutes:

{{{12000s * (1 min)/(60s) = 1200 minutes}}}

Convert to hours:

{{{1200 min * (1 hour)/(60 min) = 20 hours}}}