No sé, prueba 2,3,5,7,11,13....
Hay muchos números primos!
It follows from the definition of the binomial coefficient:
So we have
That is, 
gets absorbed into the numerator's factorial, and we introduct 
into the denominator. Now, 
, so we get
as required.
answer and explanation are in the picture.
Answer: 9.72
To make it easier you first remove( imagine)there is no decimal point. Then u multiply the number which is 4 through all the digits to get 972.
But u are not done yet because u have forgotten the decimal point. To know where to put the decimal point u have to count the number of places it was in order to know where to place it.
So it was 2 decimal places,so we count it and place it there to get 9.72
