It depends on the size of the ship. There were small(er) ships that typically had spots for about 30 to 40 rowers, but there were some very large longships that were built. The Norwegian King Olav Tryggvason's ship the Ormen Lange, was a particularly large specimen, with room for 64 rowers. There was room for passengers and cargo, however, so just because it held x so many rowers doesn't mean that was all the people it held. Ships were built for different specifications and purposes.
about 100
30-64
40-60
From 20 to 60 viking warriors
Over 100 Viking warriors.
Viking sails were usually made of wool, so they could be any color the Vikings wanted. Historical evidence suggests that many of them were striped.
45 where aboard on the ship.
The Viking longboats were long, open boats that had many sets of oars used to row the ships close to shore, or in calm winds. They used large square sails for long voyages.
20 - 30 people
This question is in the wrong section. (Traditional Viking houses were one room only.)
The Viking Symbol Mystery has 175 pages.
The Last Space Viking has 294 pages.