Question

To create an entry code, you must first choose 3 letters and then, 4 single-digit numbers. How many different entry codes can you create?

Answer 1

Since we have 26 different letters (from A to Z), for each letter that will be chosen we have 26 different possibilities.

Also, we have 10 different digits (from 0 to 9), so for each digit that will be chosen, we have 10 different possibilities.

Multiplying the number of possible outcomes for each letter and digit, we have the total number of different codes:

`\begin{gathered} 26\cdot26\cdot26\cdot10\cdot10\cdot10\cdot10 \\ =175,760,000 \end{gathered}`

Therefore the number of different codes is 175,760,000.