Aaron notes that 10% of his class is absent. If the class has 20 students, how many are absent?

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Answer 1 · 2016-11-27T06:36:18

#2# students are absent

The amount of students that are absent is #10%# of the whole class which has #20# students in it.

So

absent students#=10%(20)#
#=0.1(20)=2#

Answer 2 · 2016-11-28T11:09:39

2

#color(blue)("First principle method")#

The % sign is a unit of measurement that is worth #1/100# of whatever you are considering.

We are considering a complete class of count 20

So we need to calculate

#10%" of "20" " ->" " 10%xx20" "->" "10/100xx20#

#=200/100 = (2xxcancel(100)^1)/(cancel(100)^1) = 2#
~~~~~~~~~~~~~~~~~~~~~~~~~~
#color(blue)("Shortcut method")#

Known that #10% = 1/10# so we have #20/10 = 2#