Apprx how many 2MVA 22/0.4kV Substations can be installed or connected to a 40MVA 132/33 kV Substation?

Something is wrong here - you want to serve a group of substations with a primary voltage rating of 22 kV from a substation with a secondary rating of 33kV? Is there a typo in your question????

A simple answer is that if the ratings you cite are the actual load ratings, then one would expect that there would be no more than 20 2MVA load substations served from a single 40MVA master substation.

But in more general terms, the number of 2MVA substations can be anything you want it to be. What really matters here is that 2MVA is the rating of the load substation - that doesn't mean that each necessarily will present a load of 2MVA. The rating means that the load cannot EXCEED 2MVA. As a practical matter, the load can vary over time depending on what is being served from these substations, and as long as the composite loading of the collection of load substations does not exceed the rating of the master substation, the design is perfectly OK.

It is also possible for the aggregate of the load substations to exceed the 40MVA rating of the master substation on a short term basis - those ratings are basically transformer thermal ratings, and there is an associated time constant that also has to be considered. Short time overloading is acceptable provided there is a sufficient cooling off period after that peak.

You can't install 22kv/.4kv substation to a 132/33KV substation, You still have to provide an intermediate transformer, 40 MVA, 33/22KV transformer

after which as many as 20, 2MVa, 22kv/.4KV may be installed.

At a rough Guess 43.