Help?

A bank assigns a personal code to each of its customers. This bank currently has 1,207,354 customers. The personal code uses 2 distinct letters from 24 letters (all the letters in the alphabet except O and I), followed by n distinct numerals from 0 to 9.

What is the smallest value of n such that each customer gets a unique code?

3 answers

1207354 ≤ (24 * 24 * 10^n)

1207354 / 576 ≤ 10^n

log(1207354 / 576) ≤ n
n distinct digits means 10Pn = 10!/(10-n)! not 10^n
So adjust the calculation as needed
Of course, you know that n <= 10
missed the "distinct" ... no repetitions

24 * 23 ... not 24^2

(10-n)! ≤ 10! * 552 / 1207354