Question

find how many numbers greater than 4000 that can be formed with digits 2,3,4,5 and 6 if no digits can be used more than once in a number.

Answer 1

All 5 digit numbers 5! = 120
All 4 digit numbers begining with 4,5 of 6:3*4*3*2 = 3*4! = 72
Total = 120+72 = 192

192