Help me pls help me pls

What could explain what happened when the time was equal to 120 minutes

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.

Situation: find the age of the skull to the nearest year, enter the correct answer. a hiker in africa discovers a skull that contains 32% of its original amount of c- 14. done n = noekt 00000 no = inital amount of c-14 (at time t = 0) n = amount of c-14 at time t k = 0.0001 t = time, in years