This question caused some controversy, and a simple Google search demonstrates just why.
Top of the list is Banderas News, which nominates the mango. ("It's probably safe to say, that when asked which fruit is the most popular fruit in the world, the majority of Americans and Canadians would respond with apples or bananas. That response would be normal, but far from accurate. To the astonishment of most North Americans, mangoes are consumed worldwide by a factor of three to one over bananas and ten to one over apples.")
Next up is World Atlas, which gives the award to the tomato. ("Although tomatoes are considered as a vegetable in culinary communities, by botanical/scientific descriptors of fruits and vegetables, tomatoes are classified as a fruit. By that description, tomatoes hold the title for the world's most consumed fruit!")
Keep Fresh.com (an Australian site) agrees, and so does Dr. Michael Mosley on the BBC News website. After comparing the cases of the mango and the banana (he says the banana wins hands down), Dr. Mosley goes on: "But dwarfing all other fruits is something we may not immediately think of as a fruit: the tomato."
Triviahive goes for the mango: "To the astonishment of most North Americans, mangoes are consumed worldwide by a factor of three to one over bananas and ten to one over apples."
Wonderopolis is on the side of the banana. ("Bananas make up approximately 75% of the annual tropical fruit trade.")
According to statista.com, more watermelons than bananas (by weight) were produced globally in 2016. Is the watermelon a fruit? Statista seems unsure; it shows watermelons on its graph, but goes on: "Based on production quantities, the most popular fresh fruits worldwide in order are bananas, apples and grapes. Bananas and apples are grown on trees, and watermelons are grown on thick vines."
I'm bored with this now. But I think I've done enough to demonstrate that things like this should never be asked as quiz questions.
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