Question $5.$

A company uses a coding system to identify its clients. Each code is made up of two letters and a sequence of digits, for example AD$108$ or RR$45789.$ The letters are chosen from $A$;$D$;$R$;$S$ en $U.$ Letters may be repeated in the code. The digits $0$ to $9$ are used, but NO digit may be repeated in the code.

$5\mathrm{.}1$ How many different clients can be identified with a coding system that is made up of TWO letters and TWO digits?

$5\mathrm{.}2$ Determine the least number of digits that is required for a company to uniquely identify $700000$ clients using their coding system.

$(3)$

Total: $6$ marksQuestion $5.$

A company uses a coding system to identify its clients. Each code is made up of two letters and a sequence of digits, for example AD$108$ or RR$45789.$ The letters are chosen from $A$;$D$;$R$;$S$ en $U.$ Letters may be repeated in the code. The digits $0$ to $9$ are used, but NO digit may be repeated in the code.

$5\mathrm{.}1$ How many different clients can be identified with a coding system that is made up of TWO letters and TWO digits?

$5\mathrm{.}2$ Determine the least number of digits that is required for a company to uniquely identify $700000$ clients using their coding system.

$(3)$

Total: $6$ marks