He doesn't have enough wood for the roof explanation: If you subtract 0.8 from 1.75 that 0.95 if you then subtract 0.4 from 0.95 you get 0.55 so you can't subtract the last one 'cause if you do you'll get -0.05.
2/3x-5=1
2/3x-5+5=1+5
2/3x=6
2/3x divided by 2/3=6 divided by 2/3
x=9
Hope this helped!
Divide by 60 so 105.6/60=1,76 L/min
36/39 or 12/13 is th answer to that
I think the answer would be D