Some quick math based on average hash rates from posted lists -my math may be fuzzy but it should be in the ballpark as exchange rates flux
i5 litecoin mining - avg 40 k/hs x 100 machines = 4000 kh/s
i5 Bitcoin Mining - 17 m/s x 100 machines = 1700 mh/s
Litecoin - if you had a 100 pc's with I5 processors all running 24/7 (they would be unusable also while mining litecoin) you would clear a Little over $0.90 in Litecoin value a day
Bitcoin -If you had a 100 Pc's with I5 Processors all running 24/7 (marginally usable as the CPU would be pegged) you would clear a little over $13.00 in BTC in value a day
so if you scaled that back to 10 machines you would be getting
$0.09 in Litecoin value a day
or
$1.30 in bitcoiin value a day
plus those machines would need to be dedicated to the task and for all intents and purposes unusable
I would say not worth the time, effort and risk