1. A sold a half-interest in his motorboat to B. It was agreed that the price to be paid by B would be used in installing a motor on the vessel. Later, the vessel was destroyed by a fortuitous event. Issue: Is B's obligation to pay the price extinguished?

2. A commits the crime of theft, and is asked to return the car stolen to its owner B. If, before the car is delivered to B, it is destroyed by fortuitous event, is A's liability extinguished?

3. A owes B P700,000, guaranteed by C. B assigns his credit to X. X assigns his credit to Y. Y assigns his credit to C, the guarantor. Does A still have to pay C?

4. A has a P1,000,000 savings deposit with the Phil. National Bank. One day A borrowed P200,000 from the Bank. Without asking permission from A, the Bank subtracted the P200,000 from A's account, leaving a balance of P800,000 in A's favor. Is the bank's action proper?

5. A rented a house from B. In the contract of lease, the lessee A was given authority to assign the lease to strangers. Because of this A leased it to C. Issue: Is A released from his obligation towards the lessor B?

6. D owes C P1,000,000. F, a friend of D, approaches C and tells him: "I will pay you what D owes you." C agrees. Is there expromision here?

7. A owes B P1,000,000. A proposed to B that C will pay A's debt, and that A will be released from all liabilities. B and C agree to the proposal. Later, when B tries to collect from A, he nds out that C is insolvent. It was proved that at the time of delegation, C was already insolvent but this was not known to A. Neither was the insolvency of public knowledge. Nevertheless, B still sues A on the ground that it was A who made the proposal, and that therefore A really guaranteed C's insolvency. Is A liable?

8. D and C entered into a contract whereby D was to give C P800,000 in cash. Later, they novated the contract by stipulating that instead of cash, D would give a particular car. Subsequently, the car was destroyed by a fortuitous event. Is D obliged to give P800,000?