कौन सा वर्ग उस वेन आरेख द्वारा सबसे अच्छी तरह दर्शाया जा सकता है जिसमें एक बड़े वृत्त के अंदर दो संकेंद्रीय वृत्त होते हैं, जहाँ एक छोटा वृत्त पूरी तरह से दूसरे छोटे वृत्त के अंदर होता है (यानी A ⊆ B ⊆ C का संबंध)?

In a survey of tourist preferences, it was found that 35 people visit Manali, 45 visit Ooty, and 40 visit Shimla. Among these, 12 people visit both Manali and Ooty, 15 visit both Ooty and Shimla, and 10 visit both Manali and Shimla. If 5 people visit all three hill stations, find the number of people who visit at least two places.

In a competitive exam question based on Venn diagram sets, if the set of 'Cats' is represented by a circle, 'Paper' by a triangle, and 'Books' by a rectangle, and the intersection region containing all three shapes has the value 3, how many cats are both paper and books?