How many 4 digit numbers greater than 5000 can be formed by using the digits 2, 3, 5, 6, 7 and 8 such that digits can get repeated?

The correct option is C 864

When the repetition is allowed: All the places: Hundred’s, ten’s and unit’s can be filled by any of the digits: 2, 3, 5, 6, 7 or 8 i.e. in 6 ways.

Thousand’s place can be filled only in 4 ways. Hence no. numbers possible = $4\times 6\times 6\times 6$ = 864.