Question

How many 4 digit number can be formed using the digits 2,3,4,5,6,7, where repetition is not allowed

Answer 1

Answer:360

Step-by-step explanation:We can use permutation here:

_ _ _ _ (_ represents a digit)

The number of possibilities of the of the first blank is 6 (2,3,4,5,6,7)

Since there cant be any repeating digits therefore no. of possibilities of the 2nd digit = 6-1 = 5

Similarly for the 3rd digit it is 4

And lastly it is 3

Therefore total no. of possibilities = 6×5×4×3= 360