Combine the total number of marbles and that will the denominator.
5 + 4 + 1 = 10
Now the number of white marbles will be the numerator.
[tex]\frac{5}{10}[/tex]
Convert the fraction into a decimal by dividing the top by the bottom.
5 / 10 = 0.5
Now convert the decimal into a percent by moving the decimal point two places to the right and adding % sign.
0.5 = 50%
So, there is a 50% of choosing a white marble.