light years are units of distance not time...
1 light year = 9.4605284 × 10^15 meters
divide that by 1000 to convert to kilometers, then multiply by 600
= 5.67751704 * 10^15
-- HERES THE PROCESS----
Theres no process to determine how far a light year is- its just common knowledge (like 1760 yards per mile or 5280 feet) heres the process to solve:
You want kilometers right? that means you must move the decimal 3 places to the left because 1 meter is 1 thousandth of a kilometer.
since a light year is 9.4605284 × 10^15 meters, it is also 9.4605284 × 10^12 kilometers (scientific notation loses 3 zeros since we are moving the decimal point 3 places left)
Now we just multiply by 600 light years
answer = = 5.67751704 * 10^15