Hi, I was doing some problems in an SAT math workbook and came across this:

(all parentheses added by me to deter confusion)

1/(1+1/b) = p Which expression is 2p?

The answer given by the book is 1/ ((1/2)+(1/2b))

However, it would seem to me if p=1/(1+1/b) then 2p=2(1/(1+1/b)) = 2/(2(1+1/b)) = 2/(2+2/b)

Can someone explain this to me please?