# maths

posted by .

In 60 ounces of alloy for watch cases there are 20 ounces of gold.how much copper must be added to the alloy so that a watch case weighing 4 ounces,made from the new alloy,will contain 1 ounce of gold.......answer is 20 ounces

## Similar Questions

1. ### algebra

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?

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?
3. ### Geometry

An alloy of copper is 10% copper and weighs 25 pounds. A second alloy is 18% copper. How much (to the nearest tenth lb.) of the second alloy must be added to the first alloy to get a 13% mixture.
4. ### College Pre Calculus

anne and nancy use a metal alloy that is 19.3% copper to make jewelry. how many ounces of a 19% alloy must be mixed with a 20% alloy to form 110 ounces of the desired alloy?
5. ### 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?
6. ### algebra

How many ounces of a 19% copper alloy metal must be added to 42% ounces of a 40% copper alloy metal to produce a metal which is 31% copper alloy
7. ### math

An alloy of copper is 10% copper and weighs 25 pounds. A second alloy is 18% copper. How much (to the nearest tenth lb.) of the second alloy must be added to the first alloy to get a 13% mixture.
8. ### math

A jeweler wants to make a silver alloy to be used to make necklaces. How many ounces of a silver alloy that costs \$3.50 per ounce should be mixed with one that costs \$7.00 per ounce to make a new 30-ounce alloy that costs \$6.30 per …
9. ### math

A jeweler wants to make a silver alloy to be used to make necklaces. How many ounces of a silver alloy that costs \$3.50 per ounce should be mixed with one that costs \$7.00 per ounce to make a new 30-ounce alloy that costs \$6.30 per …
10. ### math

How many ounces of an alloy containing 30% gold on the world market must be added to 10 ounces of an alloy containing 5% to produce an alloy containing 20% gold?

More Similar Questions