There can be 35 different numbers of six digits if the digits are not allowed to repeat...
u see there are six digits out of which one is 0...since zero cant take the place value of only 5 numbers can be formed by interchanging its position except for keeping it on the place value of of the 5  numbers can attain any position..
since there r six positions so each number can attain six positions ...therefore..6*5+5 numbers can be formed ...which is equal to 35