Permutations And Combinations

Gap-fill exercise

  
Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
1. C3n15 = Cn + 315.
2. Cn + 120 = Cn - 120.
3. C12n = C8n.
4. C2n2 - n = C4n2 - n.
5. Cn18 = Cn + 218.
6. Cn8 - C37 = C27. ,
7. Cn15 : Cn - 115 = 11 : 5 .
8. C32n : C2n = 44 : 3 .
9. C8n + 2 : P4n - 2 = 57 : 16 .
10. Pn10 = 5040.