Final answer:
The negation of the statement "the train is late or my watch is fast" is "the train is not late and my watch is not fast."
Step-by-step explanation:
In this case, we can use De Morgan's laws to find the negation of the statement "the train is late or my watch is fast." De Morgan's laws state that the negation of a disjunction (OR) is the conjunction (AND) of the negations of the individual statements. So, the negation of the statement is "the train is not late and my watch is not fast."