Lawn roller

The lawn at the family house has an area of 3a. The family owns a 1.5 m wide garden roller, which is 1 m in diameter. How many times does the roller turn when rolling the whole lawn?

Final Answer:

n =  64

Step-by-step explanation:

$$\begin{gathered} S=3\text{a}\to {\text{m}}^2=3\cdot 100{\text{m}}^2=300{\text{m}}^2 \\ l=1.5\text{m} \\ D=1\text{m} \\ {S}_1=l\cdot \pi \cdot D=1.5\cdot 3.1416\cdot 1\doteq 4.7124{\text{m}}^2 \\ n=S/S_1=300/4.7124=64 \end{gathered}$$

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