Question
How many 3-digit numbers can be formed from the digits 1, 2, 3, 4 and 5 assuming that repetition of the digits is allowed.
Solution
Number of digits available = 5
Number of places for the digits = 3.
Number of ways in which place (x) can be filled = 5
m = 5
Number of ways in which place (y) can be filled = 5 (∵ Repetition is allowed)
n = 5
Number of ways in which place (z) can be filled = 5 (∵ Repetition is allowed)
p = 5
∴ By fundamental principle of counting, the number of 3-digit numbers formed.
= m x n x p = 5 x 5 x 5 = 125
Number of ways in which place (x) can be filled = 5
m = 5
Number of ways in which place (y) can be filled = 5 (∵ Repetition is allowed)
n = 5
Number of ways in which place (z) can be filled = 5 (∵ Repetition is allowed)
p = 5
∴ By fundamental principle of counting, the number of 3-digit numbers formed.
= m x n x p = 5 x 5 x 5 = 125
