Window

Peter demolished a box hole in the wall for the window frame 147×51 cm. When they come, they will find a master-fitted frame and window that glass is 13.3 cm from the hole in each direction.

Calculate how much percent less light enters the window than the hole.

Correct answer:

p =  60.8 %

Step-by-step explanation:

$$\begin{gathered} p=100\%\cdot \frac{S_1-S_2}{S_1}= \\ =100\%\cdot \frac{147\cdot 51-(147-2\cdot 13.3)\cdot (51-2\cdot 13.3)}{147\cdot 51}= \\ =60.8\% \end{gathered}$$

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