How to convert 5pmol/ml to ng/ml?? - (Jan/23/2012 )

This is in reference to oligonucleotide probe.
MW is 17709.8g/mol
Length of nucleotides in a probe....50

n=m/M
c=n/V

can you please figure it out f or me as i dnt understand

5.10^-12 X 17709.8 = x g/L

or use this link (if you have ssDNA):

http://www.promega.com/techserv/tools/biomath/calc04.htm