SOLUTION: Kayla is driving a truck loaded with 30m^3 of rock that has a total mass of 153t. An identical truck, driven by Megan, is loaded with 22m^3 of rock that has a mass of 117t. Determi

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Kayla is driving a truck loaded with 30m^3 of rock that has a total mass of 153t. An identical truck, driven by Megan, is loaded with 22m^3 of rock that has a mass of 117t. Determi      Log On


   

Question 1105297: Kayla is driving a truck loaded with 30m^3 of rock that has a total mass of 153t. An identical truck, driven by Megan, is loaded with 22m^3 of rock that has a mass of 117t. Determine the mass of the empty truck and the mass of 1m^3 of rock.
Answer by ikleyn(52887) About Me  (Show Source):
You can put this solution on YOUR website!
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T + 30*D = 153      (1)    ("truck loaded with 30m^3 of rock has a total mass of 153t")
T + 22*D = 117      (2)    {"truck loaded with 22m^3 of rock has a mass of 117t)

---------------------------Subtract eq(2) from eq(1)  ==========>

     8*D = 153 - 117 = 36    ==========>  D = 36%2F8 = 4.5 ton per m^3 is the density of the rock.


Then  from eq(1),  T = 153 - 30*D = 153 - 30*4.5 = 18 tons is the mass of the truck.

Solved.