Question

I organized an ocean cleanup and we collected a total of 25 pounds of garbage.16 pounds of garbage consisted of plastic.What percent of the garbage was plastic?

Answer 1

The answer is `64%`.

Explanation:

In order to find out the percentage from a situation, we must set up two ratios.

`16/25 = "? %"/"100%"`

is the equation you will have to use to find the percentage of how much is made out of plastic. The first way is to use cross-multiply. Meaning you will have to multiply `16` by `100` to gain `1600` as your product. Dividing `1600` by `25` gives you `64%`.

The second way to see if it's correct is by dividing `16` by `25`. This gives you a decimal of `0.64`. By doing `0.64 xx 100`, it gives you `64`. Therefore, `64%` of the trash collected was plastic.

Answer 2

64%

Explanation:

`color(blue)("Preamble")`

Percentage can be written in two ways. Although they look different they both mean the same thing.

Example: 30 percent `-> 30% -> 30/100`

Percentage really is a special fraction. What makes it special is that the bottom number (denominator) is ALWAYS 100.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
`color(blue)("Answering the question")`

All the plastic collected weighed 25 pounds
Of this there was 16 pound of plastic

The amount of plastic expressed as a fraction of the whole is `16/25`

We need to change this to percentage so the bottom number (denominator) has to end up as being 100.

Multiply by 1 and you do not change the value. However, 1 comes in many forms.

`color(green)(16/25color(red)(xx1) color(white)("d") ->color(white)("d")16/25color(red)(xx4/4) )`

`color(green)(color(white)("ddddddd")->color(white)("d")(16xx4)/(25xx4))`

`color(green)(color(white)("ddddddd")->color(white)("dd")64/100)`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Think of this as `64xx1/100`

Think of % as being the same as `xx1/100`

So `64xx1/100 ->64%`