Question: How many of the first tanks carrying the QF 6-pounder 6 cwt Hotchkiss were built?

Context paragraphs:
QF 6-pounder 6 cwt Hotchkiss: The Ordnance QF 6-pounder 6 cwt Hotchkiss Mk I and Mk II was a shortened version of the original QF 6 pounder Hotchkiss naval gun, and was developed specifically for use in the sponsons of the later Marks of British tanks in World War I, from Mark IV onwards.

QF 14 pounder Maxim-Nordenfelt naval gun: The QF 14 pounder was a 3-inch medium-velocity naval gun used to equip warships for defence against torpedo boats.  It was produced for export by Maxim-Nordenfelt (later Vickers, Sons and Maxim) in competition with the Elswick QF 12-pounder 12 cwt and QF 12-pounder 18 cwt guns.

QF 13-pounder 6 cwt AA gun: The Ordnance QF 13 pounder Mk III anti-aircraft gun, also known as 13 pounder 6 cwt, was an early British improvisation in World War I to adapt the 13 pounder field gun to anti-aircraft use.  6 cwt referred to the weight of barrel and breech (6 × 112 lb = 672 lb) to differentiate it from other "13 pounder" guns.

Ordnance BL 12-pounder 6 cwt: The Ordnance BL 12 pounder 6 cwt was a lighter version of the British 12 pounder 7 cwt gun, used by the Royal Horse Artillery in the late 19th and early 20th centuries.

RML 9 pounder 8 and 6 cwt guns: The RML 9 pounder 8 cwt gun and the RML 9 pounder 6 cwt gun were British Rifled, Muzzle Loading (RML) field, horse and naval artillery guns manufactured in England in the 19th century, which fired a projectile weighing approximately 9 lb .  "8 cwt" and "6 cwt" refers to the weight of the gun to differentiate it from other 9 pounder guns.

Mark IV tank: The Mark IV (pronounced "Mark Four") was a British tank of World War I.  Introduced in 1917, it benefited from significant developments on the first British tank (the intervening designs being small batches used for training).  The major improvements were in armour, the re-siting of the fuel tank, and easier transportation.  A total of 1,220 were built: 420 "Males", 595 "Females" and 205 Tank Tenders (unarmed vehicles used to carry supplies), which made it the most numerous British tank of the War.

QF 12-pounder 12 cwt AA gun: The 12 pounder 12 cwt anti-aircraft gun was borrowed for AA use from the QF 12 pounder 12 cwt coast defence gun with the addition of a modified cradle for higher elevation, a retaining catch for the cartridge, and an additional spring recuperator above the barrel and high-angle sights.  Writers commonly refer to it simply as "12 pounder anti-aircraft gun".  12 cwt referred to the weight of the barrel and breech (12 x 112 lb = 1,344 lb) to differentiate it from other "12 pounder" guns.

QF 6-pounder Hotchkiss: The Ordnance QF Hotchkiss 6 pounder gun Mk I and Mk II or QF 6 pounder 8 cwt were a family of long-lived light 57 mm naval guns introduced in 1885 to defend against new, small and fast vessels such as torpedo boats and later submarines.  There were many variants produced, often under license which ranged in length from 40 to 58 calibers, but 40 caliber was the most common version.

Male tank: The "Male" tank was a category of tank prevalent in World War I.  As opposed to the five machine guns of the female version of the Mark I tank, the male version of the Mark I had a QF 6 pounder 6 cwt Hotchkiss and three machine guns. By the end of World War I, tank technology was advanced enough for tanks to be both male and female.

Ordnance QF 2-pounder: The Ordnance QF 2-pounder (QF denoting "quick firing"), or simply "2 pounder gun", was a 40 mm British anti-tank and vehicle-mounted gun, employed in the Second World War.  It was actively used in the Battle of France, and during the North Africa Campaign.  As Axis tanks improved in armoured protection, it lost effectiveness, and it was gradually replaced by the 6-pounder, starting in 1942, though some remained in service until the end of the war.  In its vehicle-mounted variant, the 2-pounder was also a common main gun on British tanks early in World War II, and was a typical main armament of armoured cars, such as the Daimler, throughout the war.

Supporting paragraphs: QF 6-pounder 6 cwt Hotchkiss Mark IV tank
Answer: 1,220