+122 How many four-digit numbers \( N = \underline{a}\,\underline{b}\,\underline{c}\,\underline{d}\) satisfy all of the following conditions?
1. \(4000 \le N < 6000\)
2. \(N\) is a multiple of \(5\)
3. \(3 \le b < c \le 6\)
Sorry, I don't understand your 3rd condition! It seems to conflict with the first? No?
+122 No, just the digits \(b\) and \(c\) have to follow the third condition. The problem only said that the total number \(N\) had to follow the first condition.
Look at these numbers and see if they meet your conditions. If they don't, please let know where I went wrong.
4000 4005 4010 4015 4020 4025 4030 4035 4040 4045 4050 4055 4060 4065 4100 4105 4110 4115 4120 4125 4130 4135 4140 4145 4150 4155 4160 4165 4200 4205 4210 4215 4220 4225 4230 4235 4240 4245 4250 4255 4260 4265 4300 4305 4310 4315 4320 4325 4330 4335 4340 4345 4350 4355 4360 4365 5000 5005 5010 5015 5020 5025 5030 5035 5040 5045 5050 5055 5060 5065 5100 5105 5110 5115 5120 5125 5130 5135 5140 5145 5150 5155 5160 5165 5200 5205 5210 5215 5220 5225 5230 5235 5240 5245 5250 5255 5260 5265 5300 5305 5310 5315 5320 5325 5330 5335 5340 5345 5350 5355 5360 5365 Total = 112
