In Arun’s opinion his weight is greater than 65 Kg, but less than 72 Kg. His brother doesn’t agree with him and believes Arun’s weight is greater than 60 Kg but less than 70 Kg. Their mother, on the other hand claims his weight cannot exceed 68 Kg. If all 3 of them are correct in their estimations, then what is the average different probable weight of Arun?