CREATE TABLE table_27061 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" FLOAT)

When 120 is the number in series who is the writer?
SELECT "Written by" FROM table_27061 WHERE "No. in series" = '120'
SELECT "Written by" FROM "table_27061" WHERE "No. in series" = '120'