Question

How many odd numbers less than 1000 can be formed using the digits 0, 1, 4 and 7 if repetition of digits is allowed​

Answer 1

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The number of odd numbers less than 1000 are in the form of 1 digit , 2 digit and 3 digits

The number of one digit odd numbers less than 1000 is 2

The number of two digit odd numbers less than 1000 is 3 × 2 i.e 6

The number of 3 digit odd numbers less than 1000 is 3 × 4 × 2 i.e 24

Hence , the total number of odd numbers less than 1000 is 2 + 6 + 24 = 32