Question

I must find what is the 7 digit registration number of the 3000th boat, when the digits available are 0, 1, 2, 3, 4, 5, 6, 7, 9, the registration numbers are issued in ascending order and you cannot have 6 and 9 in the same line,

Answer 1

Ok, continuing the previous q... I'll give you a head start with the method for solving this :-

we knw that number of permutations starting wid 1 is 9360, which exceeds 3000.
so we need to zoom a bit lower

Answer 2

# of permutations starting wid 10 : 6p5 + 6p5 - 5! = ?

Answer 3

next, find # of permutations starting wid 12,
next, find # of permutation starting wid 13, <<<< here you will find 300th boat

give it a try

Answer 4

k

Answer 5

ping if u get stuck, good luck !