> How to calculate stockholders equity?

How to calculate stockholders equity?

Posted at: 2014-12-05 
100k - 80k + (210k - 110k - 20k) = 100k

Shop started the year with total assets of 100k, total liabilities of 80k. during the year the shop recorded 210k in revenue, 110k in expenses, dividends of 20k. Stock holder equity at end of year was?

a)80k

b)90k

c)100k

d)120k