SOLUTION: The metal used to make a coin is a mixture of steel and copper. The ratio, mass of steel : mass of copper is 108 : 7 The coin has a total

Question 631391: The metal used to make a coin is a mixture of steel and copper. The ratio, mass of steel : mass of copper is 108 : 7 The coin has a total mass of 230 milligrams Calculate the mass of copper in this coin.
Answer by Theo(13342) (Show Source): You can put this solution on YOUR website!
let s represent the mass of steel in the coin
let c represent the mass of copper in the coin
the mass in the coin is equal to 230
your equation is:
s + c = 230
since the ratio of steel to copper is 108/7, this means that:
steel = 108/115 times the mass of the coin.
copper = 7/115 times the mass of the coin.
this results in steel = 216 milligrams and copper = 14 milligrams
the ratio of steel to copper is 216/14 = 108/7
the sum of the mass of steel and copper is 216 + 14 = 230
---------------------
another way to look at it:
----------------------
the ratio of steel to copper is 108/7
this means that 108*x + 7*x = mass of the coin.
this means that 108*x + 7*x = 230
combine like terms to get:
115*x = 230
solve for x to get 2
this means that 108*2 + 7*2 = 230 which results in:
216 + 14 = 230
this means the mass of the coin in steel is 216 milligrams and the mass of the coin in copper is 14 milligrams.
------------------------------
still another way to look at it:
--------------------------------
ratio of steel to copper is 108/7
let s represent mass of steel
let c represent mass of copper
you get:
s/c = 108/7
solve for s to get s = 108c/7
you also know that s+c = 230
substitute for s in this equation o get:
108c/7 + c = 230
multiply both sides this equation by 7 to get:
108c + 7c = 230*7
combine like terms to get:
115c = 230*7
divide both sides of this equation by 115 to get:
c = 230*7/115 which results in c = 14
since s+c = 230, this means that s must be equal to 216.

RELATED QUESTIONS
a metal is made from copper,zinc and lead in the ratio 13:6:1. the mass of the zinc is... (answered by josgarithmetic)

a piece of string of length 85 centimeter is divided into three pieces in the ratio 2:3:5 (answered by rfer,addingup,ikleyn)

A metal alloy is 25% copper. Another metal alloy is 50% copper. How many grams of the 50% (answered by mathmate)

a solution of one peso coin is 5.4 grams.How many grams of copper 75% copper by... (answered by josmiceli,ikleyn)

The ratio of copper to tin is 23 to 2, if a bronze trophy has a mass of 2250g what is the (answered by ankor@dixie-net.com)

Please help 1. A right angles triangle has sides in the ratio 3:5:7. If the hypotenuse... (answered by Alan3354,stanbon)

Please help 1. A right angled triangle sides in the ratio 3:5:7. If the hypotenuse is... (answered by Alan3354,ankor@dixie-net.com)

Brass is an alloy the contains the metals copper and zinc. Copper typically accounts for... (answered by mananth)

The density of steel is approximately 7.8 grams per cubic centimeter. An empty steel can... (answered by josgarithmetic,ikleyn)