I know you don’t do homework, but this is an optional problem that I have spent hours on and it driving me nuts. You’re help will be most appreciated and I will be able to skip the Xanax tonight.
A baker has three kinds of fiber. A is $1.80/lb, B is 1.30 and C is .65. He makes 21 pounds of a mixture that uses all three, twice as much C as B, and will sell for a buck a pound.
I get the formula 1.8(21-3x) + 1.3x+ .65(2x) = 21 which does not give the correct answer. What am I doing wrong.
It doesn’t? I haven’t done any algebra in a long while, but the answer I got using the above seemed to check out fine.
Using the three formulas:
a + b + c = 21
1.8a + 1.3b + .65c = 21
2b - c = 0
I get a = 3, b = 6, c = 12
I suspect this is the same answer you got because after substitution your equation is the same as I would get. If that’s the wrong answer I can’t help you.
I think your formula is fine. When I do the algebra to solve for X, I come up with quantities 3, 6, and 12 for A, B, and C respectively. Given that this is a homework problem, the fact the answers are integers is a pretty strong endorsement that they’re correct. Had we gotten 5.983564 lbs for one of them, well then I’d think your formula was hosed up somehow.
What makes you think that’s not correct? Do you have an answer it ought to be? Do you trust that answer more than this one? Why?
Forget the bit about the baker making 21 pounds, and just calculate everything for making 1 pound of a mix at $1.00 a pound.
All amounts in fractional pounds, these are the equations you’re given:
That’s 25.7 cents worth of a, 37.1 cents of b, and 37.1 cents of c per pound. With rounding errors that comes to 99.9 cents per pound.
Multiply that answer by 21 pounds if you must.
I don’t know what my problem was. When solving my equation I ended up with a negative number, and then after cckeberos told me it worked I redid it and, viola, it worked perfectly. I just don’t understand it. Stupidity my have something to do with it.
You might wanna try adding more fiber to your diet…