Question

How many numbers between 100 and 1000 , can be formed with the digits, 1,2,3,4,5 if the repetition of digit is not allowed?

Answer 1

Answer:

Hence the total number lying between 100 and 1000 which can be formed with digits 0, 1, 2, 3, 4, 5, 6, 7 are 294 numbers i.e. \[{}^{8}{{P}_{3}}-{}^{7}{{P}_{2}}\]. \[\therefore \] Option (d) is the correct answer. Note: In a question like this be careful as to subtract 3 digit numbers starting with zero.

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