SOLUTION: an alloy of tin is 15% tin weighs 20 pounds. a second alloy is 10% tin. how much of the second alloy must be added to the first alloy to get a 12% mixture. the amount would be

Algebra ->  Customizable Word Problem Solvers  -> Mixtures -> SOLUTION: an alloy of tin is 15% tin weighs 20 pounds. a second alloy is 10% tin. how much of the second alloy must be added to the first alloy to get a 12% mixture. the amount would be       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 122501: an alloy of tin is 15% tin weighs 20 pounds. a second alloy is 10% tin. how much of the second alloy must be added to the first alloy to get a 12% mixture.

the amount would be ( ) pounds

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
an alloy of tin is 15% tin weighs 20 pounds. a second alloy is 10% tin. how much of the second alloy must be added to the first alloy to get a 12% mixture.
:
Let x = no. of pounds of 10% alloy that must be added
:
The resulting 12% mixture would weigh (x+20) lbs
:
A typical mixture equation
.15(20) + .10x = .12(x+20)
:
3 + .1x = .12x + 2.4
:
.1x - .12x = 2.4 - 3
:
-.02x = - .6
x = %28-.6%29%2F%28-.02%29
x = +30 lbs of 10 % tin required
:
:
Check solution, we know the final amt will weigh 20+30 = 50
.15(20) + .10(30) = .12(50)
3 + 3 = 6; confirms out solution