Q$3$: The trust game involves two players: a sender and a receiver. Both the sender and receiver are given an initial sum $m.$ The sender sends a share $x$ of their $m$ to the receiver. This amount $x$ is often called the investment. Before the investment is received by the receiver, it is multiplied by some factor $k.$ Therefore, the receiver receives $kx.$ The receiver then returns to the sender some share $y$ of their total allocation $m+kx.$ The final outcome $($payoff$)$ is the sender has $m-x+y$ and the receiver has $m+kx-y.$ Find SPE.