Nitrogen

One bag of urea containing 46 percent nitrogen weighs 25 kg. How many bags have to be purchased for fertilizing a field of 41003 square meters if the nitrogen dose is 50.0 kg per hectare?

Correct result:

n =  18

Solution:

$$\begin{gathered} S=41003{\text{m}}^2\to \text{ ha}=41003\mathrm{/}10000\text{ ha}=4.1003\text{ ha } \\ m=50\cdot S=50\cdot 4.1003=205.015\text{ kg } \\ 0.46m_1=m \\ {m}_1=m\mathrm{/}0.46=205.015\mathrm{/}0.46={\displaystyle \frac{41003}{92}}=445\frac{63}{92}\doteq 445.6848\text{ kg } \\ n=\lceil m_1\mathrm{/}25\rceil =\lceil 445.6848\mathrm{/}25\rceil =18 \end{gathered}$$

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