Let the number of days lasted by the first voyage is x and that for the second voyage is y.
It is given that the first voyage lasted 43 days longer than the second voyage.
Therefore,
x - y = 43 --- (1)
It is also given that the two voyages combined lasted a total of 1,003 days. Therefore,
x + y = 1003 --- (2)
(1) + (2) gives
2x = 1046
Divide both sides by 2.
x = 523
x + y = 1003
523 + y = 1003
y = 1003 - 523
= 480
Hence, the second voyage lasted 480 days.