Solve the problem.
-How many 5-digit numbers can be formed using the digits 1, 2, 3, 4, 5, 6, 7 if repetition of digits is not allowed?
A)2520
B)16,807
C)120
D)119

Question

Quizplus · Accepted Answer

Since repetition of digits is not allowed, the first digit can be chosen in 7 ways (from 1 to 7), the second digit in 6 ways (remaining digits after the first is chosen), the third in 5 ways, the fourth in 4 ways, and the fifth in 3 ways. Multiplying these together gives the total number of possible numbers: 7 * 6 * 5 * 4 * 3 = 2520.

Solve the Problem. -How Many 5-Digit Numbers Can Be Formed Using the Digits