Write 10.5 as a percent

The ''trick'' I like to use to convert decimals to percents is this:
CHANGING A DECIMAL TO PERCENT, MOVE 2 SPACES TO THE RIGHT
CHANGING A PERCENT TO A DECIMAL, MOVE 2 SPACES TO THE LEFT

That's an easy way to memorize the conversions between decimals and percents.

With the information given you should now understand how to do the problem you described!