What's in a word?
People these days are buying fewer newspapers.
Fewer students are opting to study science-related subjects.
Fewer than thirty children each year develop the disease.
Use less when you’re referring to something that can’t be counted or doesn’t have a plural (e.g. money, air, time, music, rain). For example:
It’s a better job but they pay you less money.
People want to spend less time in traffic jams.
Ironically, when I’m on tour, I listen to less music.
Less is also used with numbers when they are on their own and with expressions of measurement or time, e.g.:
His weight fell from 18 stone to less than 12.
Their marriage lasted less than two years.
Heath Square is less than four miles away from Dublin city centre.
You can read more about using less and fewer on the Oxford Dictionaries blog. Here you will find tips on how to use less and fewer correctly as well as exceptions to the general rules about their usage.
Communications and Marketing Technician
Source : https://en.oxforddictionaries.com/usage/less-or-fewer