How many 3 digit numbers can be formed from the digits 4 5 6 7 8 9 if repetition of digits is not allowed?
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(i) The possible 3 digit numbers using the digits 6, 0, 4 when repetition of digits is not allowed are 604, 640, 406 and 460. (ii) The possible 3 digit numbers using the digits 6, 0, 4 when repetition of digits is allowed are 400, 406, 460, 466, 444, 404, 440, 446, 464, 600, 604, 640, 644, 646, 664, 606, 660 and 666. How many 3=5×4×3=60.
How many 3The number 215 is different from 125. There are 504 different 3-digit numbers which can be formed from numbers 1, 2, 3, 4, 5, 6, 7, 8, 9 if no repetition is allowed.
How many 3Hence the correct answer is 12 codes possible.
How many three digit number can be formed from the digits 3 4 5 6 7?The hundreds digit can be one of (3, 4, 5, 6, 7): 5 choices. The tens digit can be one of the remaining 5 digits (including 8). Then the units digit can be any one of the remaining 4 digits. Therefore, 5*5*4 = 100 numbers can be formed with the given restrictions.
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