math
posted by jay .
A scientist wants to combine two metal alloys into 20 kg of a third alloy which is 60% aluminum. He plans to use one alloy with 45% aluminum content, and a second alloy with 70% aluminum content. How many kilograms of each alloy must be combined?

math 
Reiny
Number of kg of 45% alum .... x
number of kg of 70% alum .... 20x
solve for x
.45x + .70(20x) = .60(20)
(I suggest multiplying each of the 3 term by 100 first)
Respond to this Question
Similar Questions

math please help!!
Solve the problem. Anne and Nancy use a metal alloy that is 24.9% copper to make jewelry. How many ounces of a 20% alloy must be mixed with a 27% alloy to form 100 ounces of the desired alloy? 
Chemistry
Thank you so much for the help on my other question!!! An alloy (solution of metals) is 80% by volume iron. The rest is aluminum. Aluminum has a density of 2.70 g/cm³, and iron's is 7.87 g/cm³. A block of alloy measures 2.0 ft. wide … 
Chemistry
A homogenous mixture of metals is called an alloy. An alloy is found to be 30% by volume gold with the rest being aluminum. Aluminum has a density of 2.70 g/cm³. Gold has a density of 13.1 g/cm³. If a piece of alloy contains 3.70 … 
Chemistry
A 0.250g smaple of magnesiumaluminum alloy dissolves completely in an excess of HCl(aq). When the liberated H2(g) is collected over water at 29C at 752torr, the volume is found to be 297mL. The vapor pressure of water at 29C is 30.0torr. … 
math
Anne and Nancy use a metal alloy that is 23.5% copper to make jewelry. How many ounces of a 21% alloy must be mixed with a 30% alloy to form 108 ounces of the desired alloy? 
Math
There are two alloys consisting of zinc, copper and tin. The first alloy contains 25% zinc and the second alloy contains 50% copper. The percentage of tin in the first alloy is twice that in the second alloy. 200 kg of the first alloy … 
material science
A uniform compressive stress σz is applied to the surface of the metal alloy, and it may be assumed that there is no friction between the alloy and the die. This aluminum alloy has Young’s modulus E=70GPa and a Poisson’s ratio … 
material science
A uniform compressive stress σz is applied to the surface of the metal alloy, and it may be assumed that there is no friction between the alloy and the die. This aluminum alloy has Young’s modulus E=70GPa and a Poisson’s ratio … 
math
a metalworker has a metal alloy thay is 25% copper and another alloy that is 60% copper. how many kilograms of each alloy should the metalworker combine to create 90kg of a 53% coppet alloy 
Algebra
160 kg alloy contains copper and 55 percent aluminum.how much aluminum should be melted into it to make aluminum 70 percent.