Answer :
For the number to be greater than 20000 there are only two possibility.
Case 1: When numbers start with 2.
5th place will be fixed with 2.
Remaining four places can be filled in 4! ways now.
So total number of ways fir a number to start with 2 is 4! = 4× 3× 2× 1
= 24 ways
Case 2: When numbers start with 3.
5th place will be fixed with 3.
Since number is repeating so we use the formula .
Here p1= 2 as number 2 is repeated two times.
Now the remaining places can be filled in ways.
= 12 ways
So total ways = 24 + 12
= 36 ways
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