How many digits does the keypad code use?

How many digits does the keypad code use?

• A. Four digits
• B. Two digits
• C. Six digits
• D. Eight digits

Answer: (A)

Keypad codes are chosen to balance how easy they are to remember with how hard they are to guess. Four digits is a common length because it provides a practical number of possible codes—10,000 in total—from 0000 to 9999. That amount is large enough to deter casual guessing, yet still easy for most people to memorize. If the code were shorter, there would be far fewer possibilities and it would be quicker to guess; if it were longer, it would be more secure but harder to remember. So the keypad code uses four digits.

Keypad codes are chosen to balance how easy they are to remember with how hard they are to guess. Four digits is a common length because it provides a practical number of possible codes—10,000 in total—from 0000 to 9999. That amount is large enough to deter casual guessing, yet still easy for most people to memorize. If the code were shorter, there would be far fewer possibilities and it would be quicker to guess; if it were longer, it would be more secure but harder to remember. So the keypad code uses four digits.