Two ways:

First way:

That's 300 OUT OF 2000.
"OUT OF" means "OVER". So that's
300 OVER 2000 which is

Then to change that fraction to a percentage,
first change it to a decimal, by dividing
the numerator BY the denominator, or
dividing the denominator INTO the numerator,

        .15
2000)300.00
     200 0
     100 00
     100 00
          0

Then change the decimal to a percent by moving
the decimal two places right and putting on a %
mark:

  15%

Second way:





Cross multiply:





        15
2000)30000
     2000
     10000
     10000
         0

Answer:  15%

Edwin