#909 · Combinatorics · Counting
Permutations beginning with t and ending with e
How many of the permutations of the letters of *triangle* begin with and end with ?
H. S. Hall & S. R. Knight, Higher Algebra (1891) · Ch. XI. Permutations and Combinations, Examples XI.a, No. 6 (part 2)
Stuck? A gentle nudge
Your answer
Loading the math keyboard…
Type naturally — sqrt, pi, / and ^ become notation. Any equivalent form is accepted. Press Enter to check.