Composed of
three; 3
ten; 10; (arch.) book containing a collection of poems
Used in vocabulary (11 in total)
thirtieth day of the month; thirty days
thirty-first day of the month; thirty-one days
Thirty Years' War (1618-1648)
Examples (10 in total)
At least thirty students were absent.
This classroom can accommodate only thirty students.
I found a diary my father kept for thirty years.