Replace 'less' with 'fewer'.
'Less' denotes 'in small degree'.
'Fewer' denotes 'number'.
The correct sentence should be: No fewer
than hundred audiences are sitting in the hall and waiting for the final performance.
if you’re referring to people or things in the plural (e.g. houses, newspapers, dogs, students).
when you’re referring to something that can’t be counted or doesn’t have a plural. (e.g. money, air, time, music, rain).
Use of Less and Lesser.Less
|He devotes less time to his studies.|
|People want to spend less time in traffic jam.|
|There are no fewer than fifty boys in our class.|
|The workers roped no fewer than two hundred trees within ten hours.|
means 'in a small degree'. It can be used as a noun, an adjective, and an adverb.Lesser
can be used as an adjective. As an adjective, it is a step further to less.e.g.
|My income is less than yours. (Adjective)|
|Chemistry is less difficult than biology. (Adverb)|
|Choose the lesser evil of the two.|