There are more than 1/4 million species of beetle. Assume the average length of a beetle is 1 cm and the average walking speed is 10 cm per second. These beetles walk up a gang-plank that is 5 meters long onto an ark. They do this in pairs, side by side, one male and one female from each species. The pairs of beetles are spaced so there is a gap of 3 cm between species. How many hours will it take for all 1/4 million species of beetles to embark onto the ark once the first pair starts up the gangplank?