Question

The follow list gives the coefficient for the binomial expansion of (x+y)^10 what is the value of B? 1,10,45,120,210,252,210,B,45,10,1

Answer 1

Binomial follows a simple pattern, so the same going forward up to the mid point, ie 252 in this, is the same going backwards down to 1.
In this case, B = 120