Depending in the commuter rail line you took it takes about 30 to 40 minutes. You can get all the info you need on the MBTA's website. From Wilmington you can take either the Haverhill line or Lowell line into North Station. From North Station you have two options, hop on the subway's
Orange line to State street or
depending on the weather you could
also walk. When I worked in Boston
this is how I go in to work.
The best resource for you is MBTA.com and this is the Massachusetts Transit website. It is a great tool because they have an interactive site where you put in your address and it tells you the closest transportation options and the travel time. Best