A self-propelled power reaper with a $1.2 \mathrm{~m}$ wide cutter bar was operated at a forward speed of $4 \mathrm{~km} \mathrm{~h}^{-1}$. Turning loss during operation was observed to be 25 minutes per hectare. Neglecting any other losses, the field efficiency of the reaper will be
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A self-propelled power reaper with a $1.2 \mathrm{~m}$ wide cutter bar was operated at a forward speed of $4 \mathrm{~km} \mathrm{~h}^{-1}$. Turning loss during operation was observed to be 25 minutes per hectare. Neglecting any other losses, the field efficiency of the reaper will be
_____________________% .