Abank 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?

no. of different codes with the letters= nCr (24,2)

=276

no. of numerals= 10

nCr (10,n) × 276 more than or equals to 1207354

nCr (10,n) more than or equals to 4375 (whole number)

largest nCr (10,n) is when n= to 5 but that only equates to 252

so 253×276 =69552 is the different no. of codes they can make? there isnt enough for all customers