Question

How many numbers of three digits can be formed with the digits 1, 2, 3, 4 and 5

if the digits in the same number are not repeated? How many such numbers are

possible between 100 and 10,000

Answer 1

Solution:

The numbers of three digits can be formed with the digits 1, 2, 3, 4 and 5 if the digits in the same number are not repeated $=5\times 4\times3=60$

Three digit numbers: 5 $\times$ 4 $\times$ 3 = 60

Four digit numbers: 5 $\times$4 $\times$ 3 $\times$ 2 = 120

Five digit numbers: 0 (Because they’d be bigger than 10,000).

Total: 180 numbers