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How many lb of copper which costs $2/lb must be added to 3 lb of tin which costs $8/lb to make bronze which costs $4/lb?
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Let x be the amount of copper and y be an amount of tin.
Then the price of the bronze will be
.
Since it should be $4/lb, it gives you an equation
= 4. (1)
It is an equation to solve for x.
So, multiply the equation by (x+3) to rid of the denominator. You will get
2x + 24 = 4x + 12, or
2x = 24 - 12, or
2x = 12, or
x = = 6.
So, you need to mix 6 lbs of copper to get your alloy.
For other solved problem on mixtures see the lessons
- Mixture problems
- More Mixture problems
- Solving typical word problems on mixtures for solutions
- Word problems on mixtures for antifreeze solutions
- Word problems on mixtures for dry substances like coffee beans, nuts, cashew and peanuts
- Word problems on mixtures for dry substances like candies, dried fruits
- Word problems on mixtures for dry substances like soil and sand
- Word problems on mixtures for alloys
- Typical word problems on mixtures from the archive
in this site.
Also, you have this free of charge online textbook in ALGEBRA-I in this site
- ALGEBRA-I - YOUR ONLINE TEXTBOOK.