The sum of coefficients of any polynomial f(x) is equal to f(1), the value of the polynomial at x= 1.
In your case the sum of coefficients of the given polynomial is equal to f(1) = 32, as it is given.
The rest of the info is irrelevant and was given with the only goal to confuse you and to direct you onto wrong way.
// So, they actually want to check if you know firmly the right way to solve it.