A land 2

A land owner owns two parcels of land measuring 4 2/5 hectares and 6 1/5 hectares. He sells 3/4 of the total land. How many hectares of land are left?

Correct answer:

x =  2 ¹³⁄₂₀ = 53/20 ha

Step-by-step explanation:

$$\begin{gathered} a=4\frac{2}{5}=4+\frac{2}{5}=\frac{4\cdot 5+2}{5}=\frac{20+2}{5}=\frac{22}{5}=4.4\text{ha} \\ b=6\frac{1}{5}=6+\frac{1}{5}=\frac{6\cdot 5+1}{5}=\frac{30+1}{5}=\frac{31}{5}=6.2\text{ha} \\ q=1-3/4=\frac{1}{4}=0.25 \\ S=a+b=\frac{22}{5}+\frac{31}{5}=\frac{22+31}{5}=\frac{53}{5}=10.6\text{ha} \\ x=q\cdot S=\frac{1}{4}\cdot \frac{53}{5}=\frac{1\cdot 53}{4\cdot 5}=\frac{53}{20}=\frac{53}{20}\text{ha}=2\frac{13}{20}\text{ha}=2.65\text{ha} \end{gathered}$$

Try another example