Passage Summary: Since way more British people are taking expensive overseas trips now than in the past, they must have more money in their vacation budgets than they used to.

Conclusion: British people must currently have more money to spend on vacations, on average, than they did three decades ago.

Reasoning: The percentage of British people vacationing abroad has increased significantly, even though foreign travel has always been an expensive option.

Analysis: The author assumes that the increase in travel is solely due to an increase in available wealth. However, this ignores other possibilities, such as the relative cost of travel decreasing compared to other goods, or a shift in consumer preferences where people prioritize travel over other luxuries. For the conclusion to be necessary, the argument must assume that foreign travel hasn't become significantly more affordable in a way that would allow people with the same income to travel more. Look for an answer that addresses the relationship between the cost of travel and the average person's ability to pay for it.