Libby, a motor mechanic, spilled some engine oil near the open entranceway to his workshop. He immediately scrubbed it with detergent, but the surface remained slightly oily. Imagine that the following accidents took place. Clearly explain with appropriate references whether Libby would be liable for the resulting damage in each of the following situations.

1. Libby went to get some sand from the back of the workshop and the phone rang. Not wanting to miss a customer, he returned to answer the call. His back was turned for 30 seconds. During that time Nancy, a customer, entered. She slipped and broke her leg.
2. Nancy's daughter, who was a very nervous person, was walking behind her mother. She became very upset when she saw her mother fall because she knew that serious damage could result.
3. Libby wrote out a sign in very large bright letters which said 'Warningslippery floor. Do not enter and fixed it to the side of the workshop entrance. Connor, a customer with very poor eyesight, missed the sign, strode in, slipped, and broke his leg.
4. Connor screamed after his fall. This caused a customer who was filling his tank at the self-serve pump to spin round involuntarily and spray petrol into the eyes of another customer, who ran in shock down the driveway of Libby's garage. The driver of a Porsche who was entering the driveway swung his wheel to avoid the customer and crashed into a brick wall, causing more than $15,000 damage to his car.