Hi (whitepointer)$350,000 fuel divided x 40,000 tonnes = $8.75...

Hi (whitepointer)

$350,000 fuel divided x 40,000 tonnes = $8.75 per tonne.

Drivers.
Not sure after looking at your figures again how I worked out the drivers cost's.
Fuel is $8.75 per ton.
On your figures the truck company will get $12 per day for each driver for 20 to 24 hours work which I estimate the round trip will take.

Your total of $25 per tonne would leave $4.25 per tonne for each driver,and other costs of running each truck for one month.
Each driver doing 25 return trips over 24 days on an average 28 day month = 40 drivers doing 6 day week per month.Based on 1000 trips by 40 drivers.

Regards
Westcott.