In a box there are coins marked 0, 2, 3, 4, 5, 6, 8. Without repeating any digit, how many numbers can you form in the range 500 - 1000 (excluding 500 and 1000).

There are total 7 digits given - 2, 3, 4, 5, 6, 8 and 0
Between 500 and 1000 means from 501 to 999.

All of them are 3 digit numbers.
First digit - 5, 6 or 8 i.e. 3 possibilities (1 digit gets used here)
Second digit - Any one from 7-1 = 6 remaining digits i.e. 6 possibilities
Third digit - Any one from 6-1 = 5 remaining digits i.e. 5 possibilities

∴ Total numbers possible = 3 x 6 x 5 = 90.