Electricity consumption - Filip

Last year Filip was writing a long school paper. As a great conservationist of nature, however, he was unable to decide which is more ecological - to write the paper on a computer, or to write the paper by hand. Filip found out that:
the paper written on a computer and printed would have 32 pages,
Filip's computer has an input of 75 W
the power plant which supplies Filip with electricity, by burning the same amount of wood as is needed for the production of 1 kg
of paper, produces 3 MJ of electrical energy,
the paper written by hand would have 48 pages,
Filip has on hand A4 paper of standard weight 80 g⋅m−2
Help Filip and calculate in what time Filip must manage to write the paper on the computer, so that this option is equally ecological in terms of paper consumption as writing itself on paper?

Final Answer:

t =  3193.3 s

Step-by-step explanation:

$$\begin{gathered} S=0.210\cdot 0.297\doteq 0.0624 \\ m=(48-32)\cdot 0.080\cdot S=(48-32)\cdot 0.080\cdot 0.0624\doteq 0.0798 \\ A=3\cdot 1000^2\cdot m=3\cdot 1000^2\cdot 0.0798=239500.8 \\ t=A/75=239500.8/75=3193.3\text{s} \end{gathered}$$

Try another example