Permutations And Combinations

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. The continued product of first n natural numbers is called the n .
2. Factorial of proper fractions or integers are not defined.
Find the value of n in each case: (Q3 - Q10)
3.

(n + 2)! = 2550 \times n!

.
4.

(n + 1)! = 12 \times (n - 1)!

.
5.

\frac{n!}{2! (n - 2)!} : \frac{n!}{4! (n - 4)!} = 2 : 1

. &
6.

\frac{(2 n)!}{3! (2 n - 3)!} : \frac{n!}{2! (n - 2)!} = 44 : 3

.
7.

(n + 3)! = 56 (n + 1)!

.
8.

P (n, 4) = 20 \times P (n, 2)

.
9.

P (5, n) = 2 \times P (6, n - 1)

.
10.

{}^{9}P_{5} + 5 . {}^{9}P_{4} = {}^{10}P_{n}

Permutations And Combinations

Gap-fill exercise