Roshan makes pasta for dinner every 6 days. Lisa makes pasta for dinner every 4 days. If they both make pasta for dinner on May 6, what is the next day that they will both make pasta for dinner?

Atourist boat is used for sightseeing in a nearby river. the boat travels 2.4 miles downstream and in the same amount of time, it travels 1.8 miles upstream. if the boat travels at an average speed of 21 miles per hour in the still water, find the current of the river.