Question

How many numbers in the range 1000 - 9999 have no
repeated digits?

Answer 1

Answer:4536 numbers.

Explanation:

Since 1 st digit cannot be zero the first digit can be anything from 1–9 ( total 9)

The second digit ( any 10- 1 above)

The third digit ( any 10–2 above)

The last digit ( any 10–3 above)

Total 9x9x8x7 =

4536

:)