Red Lotus Restaurant had been having trouble with two waiters. They had been fighting for some time over who should get paid more. Waiter 1 argued that he should be paid more than Waiter 2 because he (Waiter 1) was older than Waiter 2. Waiter 2, however, argued that he should get paid more because he had worked at the restaurant longer than Waiter 1.

One night a customer, Sandra, ordered pumpkin soup. While waiter 2 was not looking, Waiter 1 dumped an entire packet of hot chili powder into Sandra's soup. Waiter 2 served the soup to Sandra. Upon eating the soup, Sandra, who was allergic to anything spicy, immediately fell ill and had to be rushed to the emergency room.

You are required to answer the following:

a. Briefly explain the principle of vicarious liability of employers

b. Who is responsible for the injury to the customer Sandra?