Calculate how many gram of p-nitrophenol you require to prepare 250 mL of a 11 mM solution. (Answer to 3 significant figures)
I worked it out as $$250/1000 L * (11*10^{-3}\text{ M})$$ = $$2.75\times 10^{-3} \text{ moles} \times 139.11\text{ g/mol}$$ = $$0.3825525$$
is that 0.383 or 0.382 when approximated to 3 sig figs?
Note that "Leading zeros are never significant".
When approximating/rounding-off to n significant figures, your n-th digit should be rounded-off. In this case, your answer would be 0.383.
Please refer to the Wiki link above and this site for explanations and examples on working with significant digits.