Solve the Problem $4 - \mathrm { km }$ By 6-Km Rectangle

Solve the problem.
-A satellite camera takes a rectangular-shaped picture. The smallest region that can be photographed is a $4 - \mathrm { km }$ by 6-km rectangle. As the camera zooms out, the length 1 and width $w$ of the rectangle increase at a rate of 3 $\mathrm { km } / \mathrm { sec }$ . How long does it take for the area A to be at least 4 times its original size?

A) $1.61 \mathrm { sec }$
B) $9.7 \mathrm { sec }$
C) $4.94 \mathrm { sec }$
D) $3.28 \mathrm { sec }$

Correct Answer:

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