Answer:
+e
Explanation:
The charge of an up quark is:
[tex]q_u = +\frac{2}{3}e[/tex]
The charge of a down quark, instead, is:
[tex]q_d = -\frac{1}{3}e[/tex]
In this problem, we have a particle consisting of 1 down quark and 2 up quarks, Therefore, the net charge of the particle will be
[tex]q=1(q_d)+2(q_u)=1(-\frac{1}{3}e)+2(\frac{2}{3}e)=-\frac{1}{3}e+\frac{4}{3}e=\frac{3}{3}e=+e[/tex]
So, the particle has a charge of +e.