At normal body temperature, 37 degrees Celsius, the value of Kw for water is 2.5 x 10^-14. Calculate [H3O+] and [OH-] at this temperature. Is pure water at 37 degrees Celsius acidic, neutral or basic?

I was told that this was a complicated ques. Since they only give you Kw (2.5 x 10^-14)
But the answer in my book says...
[H3O+] = [OH-]= 1.6 x 10^-7