Chapter 6.10, Problem 3P

Evaluate each of the integrals in Problems 3 to 8 as either a volume integral or a surface integral, whichever is easier.

${\displaystyle \int {\displaystyle \int r.nd\sigma }}$ over the whole surface of the cylinder bounded by and $x_{}^2+y_{}^2=1,z=0,$ and $z=3;$ r means ix $+\text{j}y+\text{k}z$.