| (a) | - | A makes a contract with B to buy B's horse if A survives C. This contract cannot be enforced by the law unless and until C dies in A's lifetime. |
| (b) | - | A makes a contract with B to sell a horse to B at a specified price, if C, to whom the horse has been offered, refuses to buy him. The contract cannot be enforced by law unless and until C refuses to buy the horse. |
| (c) | - | A contracts to pay B a sum of money when B marries C. C dies without being married to B. The contract becomes void. |