Question

A metal bar weighs 9.15 ounces. 94% of the bar is composed of copper. How many ounces of copper are in the bar?

Answer 1

The metal bar would be about 9.04onces of copper

Answer 2

To solve this you must use a proportion like so...

`(part)/(whole) = (part)/(whole)`

94 is a percent and percent's are always taken out of the 100. This means that one proportion will have 94 as the part and 100 as the whole

We want to know how many ounces of copper is in a 9.15 ounce bar that contains 94% copper. This means 9.15 is the whole and the unknown ounces of copper (let's make this x) is the part.

Here is your proportion:

`(x)/(9.15) =(94)/(100)`

Now you must cross multiply

x*100 = 9.15*94

100x = 860.1

To isolate x divide 100 to both sides

100x/100 = 860.1/100

8.601 = x

This means that a 9.15 ounce bar is composed of 8.601 ounces of copper

Hope this helped!

~Just a girl in love with Shawn Mendes