An erlenmeyer flask contains 56.7 g of KMnO4. How many grams of manganese is in the flask?

What's the percent(w/w) Mn in KMnO4. That is

%Mn = (atomic mass Mn/molar mass KMnO4)&100 = ?
56.7 g KMnO4 x (%/100) = ? g Mn.