Answer:
84
Step-by-step explanation:
Given,
The possible digits are 9 ( i.e. 1, 2, 3, 4, 5, 6, 7, 8, 9 )
Digits less than 5 = 4 ( i.e. 1, 2, 3, 4 )
Digits greater than 4 = 5 ( i.e. 5, 6, 7, 8, 9 )
Here, we need to make 3 digit number from these digits without repeating,
If digits are less than 5,
Then the possible ways = 4 × 3 × 2
= 24
If digits are greater than 4,
Then the possible ways = 5 × 4 × 3
= 60
Hence, the total ways of choosing three digits number without repeating if all digits are less than 5 or all digits are greater than 4
= 24 + 60
= 84
