Karen Samuels (Social Security number 123-45-6789) makes the following purchases and sales of stock:

Transaction Date Number of Shares Company Price per Share

Purchase 1-1-2015 300 MDG $ 75

Purchase 6-1-2015 150 GRU 300

Purchase 11-1-2015 60 MDG 70

Sale 12-3-2015 200 MDG 80

Purchase 3-1-2016 120 GRU 375

Sale 8-1-2016 90 GRU 330

Sale 1-1-2017 150 MDG 90

Sale 2-1-2017 75 GRU 500

Assuming that Karen is unable to identify the particular lots that are sold with the original purchase, determine the recognized gain or loss on each type of stock:

a. As of July 1, 2015.

b. As of December 31, 2015.

c. As of December 31, 2016.

d. As of July 1, 2017.

Please explain so that I understand.