Suppose $M^n$ has nonnegative Ricci curvature, i.e. $Ric\ge 0$. and assume $0<r\le R$. Is it ture that
$$ \frac{vol (\partial B_{r}(p))}{vol (\partial B_{R}(p))} \le \frac{vol (\partial B_{r}(0))}{vol (\partial B_{R}(0))} $$
the right hand side are balls in Euclidean space $\mathbb R^n$. Also is it ture that
$$ \frac{vol (\partial B_{r}(p))}{vol (\partial B_{R}(p))} \le 2n$$ which is clamied to be the consequence of B-G volume comparison.
