The answer is 110 since when we fix the last digit by 5 we have 6 empty places that can be filled in 6 factorial ways but since we have chosen the last digit is 5 so now 0 could not occur on the first place so we have only 5 days for the first place after removing zero and for the second place to we have five ways and then it continues for 5 factorial. And when we fix 0 at the last digit number we have 6 factorial ways to write the other first six digit numbers but in both the cases we will divide the answer that isa factorial ctorial into 3 factorial and the ans .is 6 factorial by 2 factorial into 3 factorial + 5 factorial upon 2 factorial into 3 factorial into 5 for the five ways that we can rotate the number when we fixed 5 at last
