Question 3
The beaver village library has just one stack of books. Anyone borrowing a book must write their name in the log and take the top book from the stack. Similarly, anyone returning a book must write their name in the log and place the book on top of the stack.
In the picture, the right-hand side shows the stack at the beginning of the day, and the left-hand side shows the log entries. In order, the log reads: Alba — borrow; Felix — borrow; Alba — return; Marta — borrow; Felix — return; Cato — borrow. Which book did Cato borrow?
In the picture, the right-hand side shows the stack at the beginning of the day, and the left-hand side shows the log entries. In order, the log reads: Alba — borrow; Felix — borrow; Alba — return; Marta — borrow; Felix — return; Cato — borrow. Which book did Cato borrow?