Boy ton's famous hot dogs can prepare hot dogs at a constant rate of 13 hot dogs/minute. how many hot dogs can boy ton's famous hot dogs prepare in 45 minutes?

Use stokes' theorem to evaluate c f · dr where c is oriented counterclockwise as viewed from above. f(x, y, z) = xyi + 5zj + 7yk, c is the curve of intersection of the plane x + z = 8 and the cylinder x2 + y2 = 81.