There are 171 such numbers:
1000 1010 1020 1030 1040 1050 1060 1070 1080 1090 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3010 3020 3030 3040 3050 3060 3070 3080 3090 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 4010 4020 4030 4040 4050 4060 4070 4080 4090 4100 4200 4300 4400 4500 4600 4700 4800 4900 5000 5010 5020 5030 5040 5050 5060 5070 5080 5090 5100 5200 5300 5400 5500 5600 5700 5800 5900 6000 6010 6020 6030 6040 6050 6060 6070 6080 6090 6100 6200 6300 6400 6500 6600 6700 6800 6900 7000 7010 7020 7030 7040 7050 7060 7070 7080 7090 7100 7200 7300 7400 7500 7600 7700 7800 7900 8000 8010 8020 8030 8040 8050 8060 8070 8080 8090 8100 8200 8300 8400 8500 8600 8700 8800 8900 9000 9010 9020 9030 9040 9050 9060 9070 9080 9090 9100 9200 9300 9400 9500 9600 9700 9800 9900 Total = 171
+118608 non zero, 2 of the next 3digits are 0
There are 9999-1000+1 = 9000 numbers altogether.
9 of them have 3 zeros
How many have 2 zeros
there are 9 choices for the fist digit, there are 9 choices for the other non-zero digit, there are 3 places there it can go
so
9*9*3 = 243
So I think the answer is 9+243 = 252
Guests gets 171, maybe I have double counted or maybe guest missed some.
Guest, have you included 1001 ??
Sorry Melody. You are absolutely right. I missed one condition and there are 252:
1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1020 1030 1040 1050 1060 1070 1080 1090 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3020 3030 3040 3050 3060 3070 3080 3090 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4020 4030 4040 4050 4060 4070 4080 4090 4100 4200 4300 4400 4500 4600 4700 4800 4900 5000 5001 5002 5003 5004 5005 5006 5007 5008 5009 5010 5020 5030 5040 5050 5060 5070 5080 5090 5100 5200 5300 5400 5500 5600 5700 5800 5900 6000 6001 6002 6003 6004 6005 6006 6007 6008 6009 6010 6020 6030 6040 6050 6060 6070 6080 6090 6100 6200 6300 6400 6500 6600 6700 6800 6900 7000 7001 7002 7003 7004 7005 7006 7007 7008 7009 7010 7020 7030 7040 7050 7060 7070 7080 7090 7100 7200 7300 7400 7500 7600 7700 7800 7900 8000 8001 8002 8003 8004 8005 8006 8007 8008 8009 8010 8020 8030 8040 8050 8060 8070 8080 8090 8100 8200 8300 8400 8500 8600 8700 8800 8900 9000 9001 9002 9003 9004 9005 9006 9007 9008 9009 9010 9020 9030 9040 9050 9060 9070 9080 9090 9100 9200 9300 9400 9500 9600 9700 9800 9900 Total = 252
