Aditya Gupta
Last Activity: 6 Years ago
note that you have NOT mentioned whether repetition of digits is allowed or not. hence the ques is incomplete. i am solving assuming repetition is allowed.
we have 5 places in 30000.
now, for first place, we can fill it in 3 ways using either of 0, 1, 2 since it should be smaller than 30000. the remaining 4 places can be filled with any digits with no restriction.
so, number of ways to fill the places= 3*7*7*7*7= 3*7^4
however, this also includes 00000, which is not a natural number.
hence total no of ways assuming repetition is allowed= 3*7^4 – 1
kindly approve and if u have any doubts regarding how to solve when repetition is not allowed, do let me know.