<p>A six digit number is to be formed from the digits $1$, $2$, $3$, $4$, $5$, $6$, $7$, $8$ and $9$. For each of the following cases, find how many different ways the six-digit number can be formed.</p>
<ol class="i-list"><li><div class="list-item-paragraph">The even and odd digits of the number must alternate and any digit may appear more than once.</div></li><li><div class="list-item-paragraph">The number must be odd and is less than $600\,000$ and no digit may appear more than once.</div></li><li><div class="list-item-paragraph">The number is formed using only four different digits, eg. $621313$, $255567$.</div></li></ol>

A six digit number is to be formed from the digits $1$, $2$, $3$, $4$, $5$, $6$, $7$, $8$ and $9$. For each of the following cases, find how many different ways the six-digit number can be formed.

The even and odd digits of the number must alternate and any digit may appear more than once.

The number must be odd and is less than $600\,000$ and no digit may appear more than once.

The number is formed using only four different digits, eg. $621313$, $255567$.

Arrangements with Repetition Allowed

Permutation and Combination

International Baccalaureate Mathematics: Analysis and Approaches Higher Level

2024 EJC Permutation And Combination Tutorial Q7

2024 EJC Permutation And Combination Tutorial Q7

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