# need help with mixture problems

• Nov 4th 2008, 06:25 PM
msbulldog2012
need help with mixture problems
Ground chuck sells for 1.45 per lb
how many lbs of ground round selling for 2.45 per lb should be mixed with 20lbs of ground chuck to obtain a mixture that sells for 2.05 per lb?

what would the formula be to get the answer? THANKS
really need the help
• Nov 4th 2008, 07:08 PM
Soroban
Hello, msbulldog2012!

Quote:

Ground chuck sells for $1.45 per lb. How many lbs of ground round selling for$2.45 per lb
should be mixed with 20 lbs of ground chuck
to obtain a mixture that sells for $2.05 per lb? Let$\displaystyle x$= lbs of ground round. We have 20 lbs of ground chuck at$1.45 per lb.
. . It is worth: .$\displaystyle 20 \times 1.45\:=\:29$ dollars.

We add $\displaystyle x$ lbs of ground round at $2.45 per lb. . . It is worth: .$\displaystyle 2.45x$dollars. The mixture is worth: .$\displaystyle 29 + 2.45x$dollars. .[1] The final mixture is$\displaystyle 20 + x$lbs at$2.05 per lb.
. . It is worth: .$\displaystyle 2.05(20 + x)$ dollars. .[2]

We just described the value of the final mixture in two ways!

There is our equation! . . . . $\displaystyle 29 + 2.45x \;=\;2.05(20+x)$