An explorer descends to the deepest part of a cave. Then she ascends 25 feet per minute. After 3 minutes, she is at -195 feet. What is the depth of the cave?

she rose 3*25 = 75 ft

clearly she started up from -195-75 = -270 ft

To find the depth of the cave, we need to subtract the distance the explorer descended from the elevation she reached after 3 minutes.

Given that the explorer ascends 25 feet per minute, and after 3 minutes she is at -195 feet, we can calculate the distance she descended during those 3 minutes.

The distance the explorer descended is equal to the rate of ascent multiplied by the time, but since the depth is a negative value, we need to add it instead of subtracting. So, the distance descended is 25 feet per minute multiplied by 3 minutes, which is 75 feet.

To calculate the depth of the cave, we need to subtract the distance descended from the elevation reached after 3 minutes:

Depth of cave = Elevation reached after 3 minutes - Distance descended
= -195 feet - 75 feet
= -270 feet

Therefore, the depth of the cave is 270 feet.