In the TV industry multi-camera productions are very common whether it be with sporting events, reality TV, game shows or even music festivals. For example football; football would be a very hard thing to film with a single camera as you’d have to be running up and down the pitch chasing after the ball constantly and then running to the commentary box to then getting to the goal line to then decipher whether the ball went just over the line. This is why multi-camera is good to use as you can cut to the commentary box then to one side of the field to the other.
Analysing “Mock the Week” shows that about between 6-8 cameras are probably used to film the production. Going from camera one being the establishing shot over the audience showing the host and his guests.