[student]

Okay here are the questions,
i performed a EDTA titration and received my results,
my question is calculation of Ca2+ moles in the 10mL hard water sample and ppm
okay so to get this i only have my average titre of the mL EDTA,
is moles = (vol) x  (M)
so i need to take my average volume divide it by 1000mL and times it by molarity
so now i need to work out molarit first?
molarit would by moles of the solute??? but thats what i need to work out.
not sure how do i get the moles from just having the 10mL hard water? do i use molecular weight?
but i am given a concentration of EDTA and that is 0.1000M so can i use that and say
0.1000M  x my volume? but what happens then to my average titre?
any suggestions?
calculation of total moles of Mg2+ and Ca2+ in the 10mL hard water sample?
okay so since its a 1:1 ratio, do i square my Ca2+ to get the answer?
any suggestions of how or what i can read to help me get to my answer?
thank you