Oxides and Oxoanions

Q. Which of the following oxide is not amphoteric in nature?

1. ZnO
2. PbO
3. CuO
4. SnO

Q. Among the given set of oxides the sets in which both the oxides are not amphoteric is/are: $M{n}_2{O}_7,Cr{O}_3,C{r}_2{O}_3,CrO,V_2{O}_5,V_2{O}_4$

1. $V_2{O}_5,C{r}_2{O}_3$
2. $M{n}_2{O}_7,Cr{O}_3$
3. $CrO,V_2{O}_4$
4. $V_2{O}_5,V_2{O}_4$