105 goats, 140 donkeys and 175 cow have to be taken across a river. There is only one boat which will have to make many trips in order to do so. The lazy boatman has his own conditions for transporting them. He insists that he will take the same number of animals in every trip and they have to be of the same kind. He will naturally like to take the largest possible number each time. Can you tell how many animals went in each trip?

To find the largest number of animals, we should find HCF of 105, 140 and 175


Prime factors of 105 = 3 × 5 × 7


Prime factors of 140 = 2 × 2 × 5 × 7


Prime factors of 175 = 5 × 5 × 7


Therefore HCF of 105, 140 and 175 is: 5 × 7 = 35


Hence, 35 animals went in each trip


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