Asubmarine is currently at a depth of 235 feet below sea level. it can descend at a rate of 5 feet per second. if the submarine descended for 2-1/2 minutes what would the depth be?

Haruka hiked several kilometers in the morning. she hiked only 66 kilometers in the afternoon, which was 25% less than she had hiked in the morning. how many kilometers did haruka hike in all?

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.

For questions 1–3, use the differential equation given by dx equals x times y divided by 3, y > 0.