6/40 as a percentage is 15.00%. This simple figure tells you that the fraction represents fifteen parts out of every hundred, rounded to two decimal places.
The fraction 6/40 can be reduced to 3/20, which is a handy way to see the same value in a smaller form. Both versions show the same proportion, just expressed with different numbers.
In everyday use, you might see this percentage on a discount tag, a test score, or a data chart. Knowing that 6/40 equals 15 % helps you quickly understand the size of the part compared to the whole.