.
Airplane + 50 gallons of fuel weights 2175 pounds. (1)
Airplane + 18 gallons of fuel weights 1999 pounds. (2)
----------------------------------------------------------Subtract (2) from (1). You will get
32 gallons of fuel weight 2175 - 1999 = 180 pounds. ====>
====> 1 gallon of fuel weights = 5.625 pounds.
(Airplane + 60 gallons of fuel)'s weight = (Airplane + 50 gallons of fuel weight) + weight of 10 gallons of fuel =
2175 + 10*5.625 = 2231.25 pounds.
Answer. Airplane with 60 gallons of fuel weights 2231.25 pounds.