Mathematics 9709 · AS & A Level · Sampling and estimation

Sampling and estimation — practice question

Determine the number of distinct arrangements that can be formed from the $9$ letters in SEVENTEEN for each case given below.
(i)[2]

One of the letter Es occupies the centre, with $4$ letters on either side.

(ii)[3]

No E sits beside another E.

(iii)[1]

Find the number of possible selections which contain exactly 2 Es and exactly 2 Ns.

(iv)[4]

Find the number of possible selections which contain at least 2 Es.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: Correct permutation method, for example $\frac{8!}{2!3!}$.

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