SOLUTION: A potting mixture contains 12.0% peat moss and 6.00% vermiculite. How much peat and how much vermiculite must be added to 100kg of this mixture to produce a new mixture having 15.0

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A potting mixture contains 12.0% peat moss and 6.00% vermiculite. How much peat and how much vermiculite must be added to 100kg of this mixture to produce a new mixture having 15.0      Log On


   

Question 1146676: A potting mixture contains 12.0% peat moss and 6.00% vermiculite. How much peat and how much vermiculite must be added to 100kg of this mixture to produce a new mixture having 15.0% peat and 15.0% vermiculite?
Please show all the steps.
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
Add p kg of peat moss
Add v kg of vermiculite
Wanted: 15% peat moss and 15% vermiculite



Simplify and solve this system.

.
.
system%280.85p-0.15v=3%2C-0.15p%2B0.85v=9%29


system%2817p-3v=60%2C-3p%2B17v=180%29

If add corresponding members and simplify that, system to use can be
system%287p%2B7v=120%2C17p-3v=60%29

If do E1 * 3, and E2 by 7, system is
system%2821p%2B21v=360%2C119p-21v=420%29

p=39%2F7
highlight%28p=5.6%29-------kilograms peat moss
-
v=%28120-7%2839%2F7%29%29%2F7

v=11%264%2F7
highlight%28v=11.6%29----------kilograms vermiculite