Question

what number we will add to get 30 by using the numbers 1 ,3 ,5 ,7, 9, 11 ,13 ,15.

Answer 1

Hi

Here is ur answer

Here we are going to use permutation as a method to find answer

As we have to choose any numbers from the above number to get 30 the chosen number should not be repeated.

so,   1! = 1

       2! = 2 ×1

       3! = 3×2×1

      4! = 4×3×2×1 and so on..

Here,

 11 + 13 + 3! = 24 + (3)(2) = 24 +6 = 30

Thus proved....

Hope it helps u

And this ! symbol is known as factorial..