Problema Solution
A certain mine yields low-grade oil shale containing 19.0 U.S. gallons of oil per ton of rock, and another mine has shale yielding 30.0 gal./ton. How many tons of each must be sent each day to a processing plant that processes 25000 tons of rock per day, so that the overall yield will be 22.0 gal./ton?
Answer provided by our tutors
let
x = the tones of the first 19 gal/ton mine
y = the tones of the second 30 gal/ton mine
25000 tons of rock per day are processed
x + y = 25000
the overall yield will be 22.0 gal./ton
19*x + 30y = 22*25000
by solving the system of equations
x + y = 25000
19*x + 30y = 22*25000
we find
x = 18,181.82 tons
y = 6,818.18 tons
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