Correct Answer - Option 3 : 180
Given:
Can be formed by using 9, 8, 7, 6, and 5 without repetitions.
Calculation:
The number of 3-digit numbers (greater than 100) will be 5P3,
The number of 4-digit numbers (less than 10,000) will be 5P4 .
the total numbers formed greater than 100 and less than 10,000 is,
⇒ 5P3 + 5P4
⇒ 5!/(5 – 3)! + 5!/(5 – 4)!
⇒ 120/2 + 120/1
⇒ 60 + 120
⇒ 180
∴ Such numbers formed are 180
