Question

A mobile number consists of ten digits. The first four digits of the number are $9,9,8\text{ and }7$ . The last three digits are $3,5\text{ and }5$ . The remaining digits are distinct and make the mobile number, the greatest possible number. What are these digits?

Answer 1

Hint: There are ten possibilities for any digit of a phone number. The possibilities are 0,1,2,3,4,5,6,7,8, and 9 are in the increasing order of their magnitudes.