The perimeter of a rectangle is increasing at while its width is growing at

MATHEMATICS · Subjective · AP · Calculus AB · Contextual Applications of Differentiation · Contextual Applications of Differentiation

Problem

The perimeter of a rectangle is increasing at

10\,\text{cm\,/s}

while its width is growing at

1.5\,\text{cm\,/s}

. Determine the rate at which its length is changing at that instant.