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A plate has 3 letters and 2 digits, how many plates

Step by step, with the reason for every step · Counting choices · Probability

Step by step

The question

Question: A plate has 3 letters (A to Z) and then 2 digits (0 to 9).

How many plates are there?

1 Count the choices

2 Multiply

Every choice goes with every other choice.

So we multiply them all: 26 × 26 × 26 × 10 × 10.

plates = 26 × 26 × 26 × 10 × 10

This is the counting principle: multiply the number of choices.

counting principle:
multiply the choices

Careful!

We do not add the choices.

Every choice goes with every other one, so we multiply.

Careful: not 26 + 26 + 26 + 10 + 10 = 98 ✗

26 times 26 is 676.

676 times 26 is 17576.

17576 times 10 is 175760.

175760 times 10 is 1757600.

26 × 26 = 676
676 × 26 = 17576
17576 × 10 = 175760
175760 × 10 = 1757600

So there are 1757600 plates.

plates = 1757600

3 Check

Let's check in another order.

First 26 times 26 times 10 times 10 is 67600.

26 × 26 × 10 × 10 = 67600

Then 26 times 67600 is 1757600.

The same.

So the answer is right!

26 × 67600 = 1757600

Let's look back.

First: count the choices.

Then: multiply.

Last: check.

Answer
plates = 1757600

Your turn

Try this one yourself, then check:

Show the answer
plates = 6760

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