Numbers with 1 in the thousands postion = 6 --> 6*1000 = 6000
Numbers with 2 in the thousands postion = 6 --> 6*2000 = 12000
Numbers with 5 in the thousands postion = 6 --> 6*5000 = 30000
Numbers with 7 in the thousands postion = 6 --> 6*7000 = 42000
Numbers with 1 in the hundreds postion = 6 --> 6*100 = 600
Numbers with 2 in the hundreds postion = 6 --> 6*200 = 1200
Numbers with 5 in the hundreds postion = 6 --> 6*500 = 3000
Numbers with 7 in the hundreds postion = 6 --> 6*700 = 4200
Numbers with 1 in the tens postion = 6 --> 6*10 = 60
Numbers with 2 in the tens postion = 6 --> 6*20 = 120
Numbers with 5 in the tens postion = 6 --> 6*50 = 300
Numbers with 7 in the tens postion = 6 --> 6*70 = 420
Numbers with 1 in the ones postion = 6 --> 6*1 = 6
Numbers with 2 in the ones postion = 6 --> 6*2 = 12
Numbers with 5 in the ones postion = 6 --> 6*5 = 30
Numbers with 7 in the ones postion = 6 --> 6*7 = 42
Adding up everything = 6666 + 13332 + 33330 + 46662 = 99990
Answer should be E.
Kudos Please... If my post helped.