Answer
a) $0.5\%$
b) $0.53\%$
Work Step by Step
a) To round to the nearest tenth, inspect the digit in the hundredths position.
$0.5\underset\uparrow269\%$$\Rightarrow$ since $\lt5$, round down
$0.5269\%\approx0.5\%$
b) To round to the nearest hundredth, inspect the digit in the thousandths position.
$0.52\underset\uparrow69\%$$\Rightarrow$ since $\geq5$, round up
$0.5269\%\approx0.53\%$