My interpolation concurs with yours, 1/60... I got 11C and 63lb/h (so, call it 10.5GPH).
However my figures are: (in lb)
Start up & taxi = 10
Trip = 3.2 x 63 = 201.6
Climb = 3 mins @ 63lb/h = 3.2; + 1USG (=6.5lb) = 9.7
Reserve - 30% of trip = 0.3 x 201.6 = 60.5
Descent = 10 mins x 63 = 10.5
So total = 292.3lb.
This is closest to (A) 286lb... which is marked as the correct one. But my answer being that far off suggests that there is something amiss in my calculations.
Tinstaafl.... climb fuel is not provided. Neither is distance ADEP - ADES. Which is why I am lost! This feedback is from a school that's an anagram of "Oxdorf".