Answer
$5.4 cm^2$
Work Step by Step
The area is given by: $A= L \times W$
The differential form can be evaluated as follows:
$dA=\dfrac{\partial A}{\partial L} dL + \dfrac{\partial A}{\partial W} dW$
Here, $dA=(24) \times (0.1)+(30) \times (0.1)$
or, $dA=2.4 cm^2+3.0 cm^2$
Hence, we have $dA=5.4 cm^2$