Given the sets of digits {1, 3, 4, 6, 8}, how many different numbers between 40,000 and 80,000 can be writtenusing these digits if repetition of digits is allowed?
A) 1250
B) 3125
C) 120
D) 1875
E) 22

Question

Quizplus · Accepted Answer

To form a number between 40,000 and 80,000, the first digit must be either 4 or 6. For each of the 5 positions in the number, there are 5 choices of digits (since repetition is allowed). Thus, there are 2 choices for the first digit and 5 choices for each of the remaining 4 digits, resulting in 2 * 5^4 = 1250 different numbers.

Given the Sets of Digits {1, 3, 4, 6, 8}