Question
How many numbers are there between 999 and 10000 such
that at least one of their digits is 5?Solution
There is no digit to be 5 on any place in 4 digitsnumber from 1000 to 9999 = 8*9*9*9 (because of at 1000s place 0 and 5 both cannot come so 8 chances like wise for the unit,10s and100s place 5 cannot come so chance will be 9) =5832 Total number between 999 and 10000 = 9000 So, required numbers are =9000–5832=3168
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