What is the tens digit of the positive integer r ?
(1) The tens digit of ~$\frac{r}{10}$~ is 3.
(2) The hundreds digit of 10r is 6.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
10*r=6xx,则r=6xx/10,十位就是6
tens digit是十位...我以为是十分位...