The following list gives the coefficients 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

Situation: an archaelogist in turkey discovers a spear head that contains 54% of its original amount of c-14. n = noekt no = inital amount of c-14 (at time t = 0) n = amount of c-14 at time t k = 0.0001 t = time, in years find the age of the spear head to the nearest year