Dimensions 30111

The hall has dimensions of 60m, 28m, and a height of 3m. How many hours will it take to paint it if it takes 3 minutes to paint 1 square meter? The walls and ceiling are painted, and the windows take up 1/3 of the total area that needs to be painted.

Correct answer:

t =  73.6 h

Step-by-step explanation:

$$\begin{gathered} a=60\text{m} \\ b=28\text{m} \\ c=3\text{m} \\ S=a\cdot b+2\cdot (a+b)\cdot c=60\cdot 28+2\cdot (60+28)\cdot 3=2208{\text{m}}^2 \\ {S}_1=S-S/3=2208-2208/3=1472{\text{m}}^2 \\ {t}_1=S_1\cdot 3=1472\cdot 3=4416\text{min} \\ t=t_1\to \text{h}=t_1:60\text{h}=4416:60\text{h}=73.6\text{h}=73.6\text{h} \end{gathered}$$

Try another example