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?

2 Answers
Feb 22, 2018

Answer:

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.

Feb 23, 2018

Answer:

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.
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#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)#
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Think of this as #64xx1/100#

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

So #64xx1/100 ->64%#