The Number of four-digit numbers strictly greater than 4321 that can be formed using the digits 0,1,2,3,4,5 (repetition is allowed) is:

 Answer

(1) The number of four - digit numbers starting with 5 is equal to = 1×6×6×6 = 216

(2) Starting with 44 and 45 is equal to = 2×6×6 = 72

(3) Starting with 433, 434,435 is equal to = 3×6 = 18

(4) Remaining Numbers are 4322, 4323, 4324, 4325 is equal to 4.

So total numbers are,

216+72+18+4 = 310