The altitude of a triangle is increasing at a rate of2500centimeters/minute while the area of the triangle is increasing at a rate of1000square centimeters/minute. At what rate is the base of the triangle changing when the altitude is9000centimeters and the area is91000square centimeters? (Answer?) centimeters/minute

Note: The "altitude" is the "height" of the triangle in the formula "Area=(1/2)*base*height". Draw yourself a general "representative" triangle and label the base one variable and the altitude (height) another variable. Note that to solve this problem you don't need to know how big nor what shape the triangle really is.