Can someone please show me how to work this out....I'm desperate!

Here's the question

Calculate the percentage composition of iron(II) nitrate 6-water Fe(NO3)2.6H2O, otherwise referred to as "iron nitrate hexahydrate" - the normal form of iron(II) nitrate hexahydrate produced by crystallization.

28 %

Work out the Mr of the compound (Fe= 55.85, (NO3)2=124.02, 6H2O= 18.02) = 197.89

Divide the Mr of Fe by that number to get a percentage