To solve this you must use a proportion like so...
[tex]\frac{part}{whole} = \frac{part}{whole}[/tex]
15 is a percent and percent's are always taken out of the 100. This means that one proportion will have 15 as the part and 100 as the whole
We want to know out of what number is 13.5 15% of. This means 13.5 is the part and the unknown (let's make this x) is the whole.
[tex]\frac{13.5}{x} =\frac{15}{100}[/tex]
Now you must cross multiply
13.5*100 = 15*x
1350 = 15x
To isolate x divide 15 to both sides
1350/15 = 15x/15
90 = x
This means that 15% of 90 is 13.5
Hope this helped!
~Just a girl in love with Shawn Mendes
