SOLUTION: Weighted Averages.
A car radiator has a capacity of 14 quarts and is filled with a 20% antifreeze solution. How much must be drained off and replaced with pure antifreeze to o
Algebra.Com
Question 164965This question is from textbook
: Weighted Averages.
A car radiator has a capacity of 14 quarts and is filled with a 20% antifreeze solution. How much must be drained off and replaced with pure antifreeze to obtain a 40% antifreeze solution?
This question is from textbook
Found 2 solutions by nerdybill, ptaylor:
Answer by nerdybill(7384) (Show Source): You can put this solution on YOUR website!
.
Let x = amount drained and replaced w/pure antifreeze
.
"antifreeze left" + "added antifreeze" = "antifreeze in new mixture"
.20(14-x) + x = .40(14)
2.8 - .20x + x = 5.6
.80x = 2.8
x = 3.5 quarts
Answer by ptaylor(2198) (Show Source): You can put this solution on YOUR website!
Let x=amount that needs to be drained off and replaced with pure antifreeze
Now we know that the amount of pure antifreeze left after x amount is drained off (0.20(14-x)) plus the amount of pure antifreeze added(x) has to equal the amount of pure antifreeze in the final mixture (0.40(14)). So, our equation to solve is:
0.20(14-x) + x=0.40*14 get rid of parens (distributive)
2.8-0.20x+x=5.6 subtract 2.8 from each side
2.8 - 2.8-0.20x+x=5.6-2.8 collect like terms
0.80x=2.8 divide each side by 0.80
x=3.5 qts-----------------------------------ans
CK
0.20*10.5+3.5=5.6
2.1+3.5=5.6
5.6=5.6
Hope this helps---ptaylor
RELATED QUESTIONS
the radiator of an car has a capacity of 16 quarts. it is presently filled with a 20%... (answered by josgarithmetic)
a car radiator has a capacity of 16 quarts and is filled with a 25% antifreeze solution.... (answered by stanbon)
A car radiator has a capacity of 16 quarts and is filled with a 25% antifreeze solution. (answered by nerdybill)
the radiator of an automobile has a capacity of 16 quarts. it is presently filled with a... (answered by josgarithmetic)
A car radiator has a 16 quart capacity and is currently filled with a 40% antifreeze... (answered by nerdybill,josmiceli)
a car radiator has a capacity of 16 quarts and is filled with a 25% anifreeze solution,... (answered by stanbon)
Otto's car radiator contains 20 quarts of a 25% antifreeze solution. How many quarts of... (answered by josgarithmetic)
a car radiator has a capacity of 16 quartz and is filled with a 25% antifreeze solution.... (answered by mananth,josgarithmetic,greenestamps)
The capacity of a car radiator is 18 quarts. If it is currently filled with a 20%... (answered by josmiceli)