Maria

Maria has decided to plant grapes in the garden behind her house. His neighbor Ben has grown grapes successfully for a long time and has given Maria advice on how to plant vines. Ben told her to plant them 3 meters apart in rows and 3 meters apart. Maria measured the size of her garden and learned that it's a rectangle with sides of 25 meters and 35 meters. How many vines should Maria buy?

Correct answer:

n =  70

Step-by-step explanation:

$$\begin{gathered} a=25\text{m} \\ b=35\text{m} \\ d=3\text{m} \\ {a}_1=(a-d)/d=(25-3)/3=\frac{22}{3}=7\frac{1}{3}\doteq 7.3333 \\ {b}_1=(b-d)/d=(35-3)/3=\frac{32}{3}=10\frac{2}{3}\doteq 10.6667 \\ {a}_2=\lfloor a_1\rfloor =\lfloor 7.3333\rfloor =7 \\ {b}_2=\lfloor b_1\rfloor =\lfloor 10.6667\rfloor =10 \\ n=a_2\cdot b_2=7\cdot 10=70 \end{gathered}$$

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