A five-row [tex]20 \, \text{cm}[/tex] manual transplanter is pulled at a speed of [tex]1.0 \, \text{km/h}[/tex]. How much area will be planted in one day of 8 hours if the field efficiency is [tex]80\%[/tex]?

A. [tex]0.50 \, \text{ha}[/tex]
B. [tex]0.60 \, \text{ha}[/tex]
C. [tex]0.64 \, \text{ha}[/tex]
D. [tex]0.70 \, \text{ha}[/tex]



Answer :

To determine how much area will be planted in one day, follow these steps.

1. Determine the total width covered by the transplanter:
- The transplanter has 5 rows, and each row is 20 cm wide.
- The total width covered = number of rows × width per row
[tex]\[ \text{Total width} = 5 \times 20 \ \text{cm} = 100 \ \text{cm} \][/tex]

2. Convert the total width from centimeters to kilometers:
- 1 km = 100,000 cm
[tex]\[ \text{Total width in km} = \frac{100 \ \text{cm}}{100,000 \ \text{cm/km}} = 0.001 \ \text{km} \][/tex]

3. Calculate the distance covered in one day, taking into account the field efficiency:
- The speed of the transplanter is 1.0 km/h.
- It operates for 8 hours a day.
- The field efficiency is 80%, meaning only 80% of the time is effectively used.
[tex]\[ \text{Distance covered} = \text{Speed} \times \text{Hours per day} \times \text{Field efficiency} \][/tex]
[tex]\[ \text{Distance covered} = 1.0 \ \text{km/h} \times 8 \ \text{hours} \times 0.80 = 6.4 \ \text{km} \][/tex]

4. Calculate the area planted in hectares:
- Area is given by multiplying the distance covered by the width in kilometers.
- 1 square kilometer = 100 hectares (ha).
[tex]\[ \text{Area planted} = \text{Distance covered} \times \text{Total width in km} \][/tex]
[tex]\[ \text{Area planted} = 6.4 \ \text{km} \times 0.001 \ \text{km} = 0.0064 \ \text{sq. km} \][/tex]
[tex]\[ \text{Area planted in hectares} = 0.0064 \ \text{sq. km} \times 100 = 0.64 \ \text{ha} \][/tex]

Therefore, the area that will be planted in one day of 8 hours is:

c. 0.64 ha