Question

if none of the digits 3,5,7,8,9 can be repeated how many different numbers greater than 7000 may be formed?(Use permutation combination)​

Answer 1

Step-by-step explanation:

All 5 digit numbers are greater than 4 digit numbers. Hence if we have a 5 digit number

we can have 3 at 10 thousand's place.

With that 5! factorial would be the answer.

Now for 4 digit numbers all number greater than 7000.

So at thousand's place you need to have a digit equal or greater than 7, i. e, 7,8,9 would do! So for this 3×3!.