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In this problem we're going to look at a percent increase
or decrease situation. Determine the percent increase or decrease for the
change from 20 to 30.
Round percent to the nearest whole number. So we're going from
20 to 30. So from 20 to 30,
that's a change of 10 and that's an increase
of 10, so what we want to do is to try to write
a percent question, and then change that to
a percent equation. So I'm going to write the question:
10 is what
percent of 20
because when we work with percent increase or decrease, it's
always the percent of the original
number that we are interested in. So since we increased from 20
we want to know 10 is what percent of 20
so there's our percent question, let's write that as a percent equation. So I
have 10
'is' is equals, what percent
is X, and then times 20, so I want to write my final result as a percent.
I'm going to divide both sides by 20 to move the 20
across the equal sign, so 10 over 20 equals
X. I'm going to perform that division.
10 divided by 20 is 0.50,
and then write that as a percent, moving the decimal,
and including a percent symbol, that's going to be
50%. So to
address the original equation, or I should say the original question
I'm going to write the change from
20 to 30
is a 50% increase