CREATE TABLE table_5029 ("Name" TEXT, "Country" TEXT, "Displacement  ( tons ) " FLOAT, "Armament" TEXT, "Weight of discharge" TEXT, "Speed" TEXT)

How much Displacement (tons) has an Armament of 2 x -inch (mm), 16 x -inch (mm)?
SELECT COUNT("Displacement (tons)") FROM table_5029 WHERE "Armament" = '2 x -inch (mm), 16 x -inch (mm)'
SELECT COUNT("Displacement (tons)") FROM "table_5029" WHERE "Armament" = '2 x -inch (mm), 16 x -inch (mm)'