SOLUTION: There are available 10 tons of coal containing 2.5% sulfur and also supplies of coal containing .80% and 1.10% sulfur respectively. How many times of each of the latter should be

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Question 902037: There are available 10 tons of coal containing 2.5% sulfur and also supplies of coal containing .80% and 1.10% sulfur respectively. How many times of each of the latter should be mixed with the original 10 tons to give 20 tons
containing 1.7% sulfur?
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
x+y=10
.025*10+.008*x+.011*y=20*.017=.34
.25+.008*x+.011*y=.34
.008*x+.011*y=.09
x+y=10,
0.008*x+0.011*y=0.09
x=10-y
0.008*(10-y)+0.011*y=0.09
0.08-0.008y+0.011*y=0.09
0.003*y=0.01
y=3.33333333 at 1.1%
x=10-y
x=6.66666667 at 0.8%
check
0.008*6.66666667+0.011*3.33333333=0.09
0.53333333e-1+0.36666667e-1=0.09
0.09=0.09
ok