We assign fruits to kids in a line. Starting from the first kid, we assign pears to every three kids (1,4,7...). Starting from the last kid, we assign apples to every five kids. Nine kids get both pear and apple. How many kids here?
What's your answer?
What's your guess for other people's answer (if there are multiple, use comma to seperate, e.g, 1,2,4)?