To deliver all the coal, you need to pass by 6 coal / 2 coal/station = <<6/2=3>>3 stations
To deliver all the iron, you need to pass by 12 iron / 3 iron/station = <<12/3=4>>4 stations
To deliver all the wood, you need to pass by 2 wood / 1 wood/station = <<2=2>>2 stations
So 4 stations are needed to deliver everything, so 4 stations * 25 minutes/station = <<4*25=100>>100 minutes are needed
#### 100