Answer:
There would be [tex]120[/tex] of them.
Step-by-step explanation:
There are [tex]6[/tex] distinct letters in the word "[tex]\verb!theory![/tex]".
Hence, there would [tex]6[/tex] possible choices for the first letter that was selected.
Since the chosen card won't be placed back in the pool, there would be only [tex](6 - 1) = 5[/tex] possible choices for the second letter.
Likewise, there would be [tex](6 - 2) = 4[/tex] choices for the third letter.
[tex]6 \times 5 \times 4 = 120[/tex]. In other words, there are [tex]120[/tex] possible ways to draw three cards out of [tex]6[/tex] one after another.
Since the question states that the order of the cards matters, it won't be necessary to eliminate repetitions such as "[tex]\verb!the![/tex]" and "[tex]\verb!het![/tex]" from the number of combinations.