Question

What is the probablity of making an even number of 4 digits using 1, 2, 3 and 4 without any digit being repeated

Answer 1

Total 24 numbers can be formed without repeating a digit.

let our four digit number be W X Y Z .

Here we have 4 options for filling W as no digit is getting repeated.

Now, we have only 3 number for filling X as one of the digit has been taken by X.

Now, we have only 2 number for filling Y as two digits are taken by X and Y.

Finally we have only 1 number left for filling Z as rest three numbers are taken by W, X and Y .

So our required number of solution will be 4*3*2*1 = 24