Answer :
Answer:
- 400 sets
Step-by-step explanation:
- First digit- 1 option (9)
- Second digit - 10 options (0 to 9)
- Third digit - 10 options (9 to 9)
- Fourth digit - 4 options (6, 7, 8, 9)
Possible number of sets:
- 1*10*10*4 = 400
Answer:
Step-by-step explanation:
Possible number of sets: