Answer:
See the answer below
Step-by-step explanation:
P can displace Q from its salt solution means that P is more reactive than Q.
Q cannot displace R from its salt solutions means that R is more reactive than Q.
a) There is no information as to which of P and R has the capacity to displace one another from their salt solutions. Hence, the most reactive metal can be either of P and R.
b) When P displaces Cu from CuSO4 solution, the equation can be represented below (assuming that P is monoatomic):
![P + CuSO_4 --> P_2SO_4 + Cu](https://img.qammunity.org/2021/formulas/chemistry/high-school/p2vhudj9imwhox6qe29xaskosvtnlm1cji.png)
Hence, the product formed is
![P_2SO_4](https://img.qammunity.org/2021/formulas/chemistry/high-school/ycajo718x4edk7fr77w9vdiqouvugid0s0.png)