Percent problems

The price of a wedding gown was decreased by $36\mathrm{\%}$. How many percent should the new price be increased so that the gown costs as much as before the discount?

The results of a survey considering the support for political parties $Y$ and $Z$ are presented in the table below. a) How many percentage points have the support for party $Z$ decreased? b) How much has the percentage of people supporting party $Y$ increased? $$\begin{array}{|ccc|}\hline & \text{February}& \text{March}\\ Y& 16\mathrm{\%}& 20\mathrm{\%}\\ Z& 10\mathrm{\%}& 8\mathrm{\%}\\ \hline\end{array}$$

Find the number by $1.6{}^{\text{o}}/{}_{\text{oo}}$ bigger than $500$.

The number of members of a certain golf club was increasing for the last three years by $20\mathrm{\%}$ a year. How many members were there in the club three years ago, assuming that the number of them amounted to $216$ a year ago?