You’re right as well.
When I first saw the picture, I was ready to solve it algebraically, by converting the animals to abc. However, somebody pointed out that all I had to do was add up all the weights and divide by two, because the animals appear twice.
From there, it was easy to figure the weight of each.
Dog = 27kg
Cat =7 kg
Rabbit = 3kg
Dog = 17kg
Since there were 3 animals, 54 - 3 = 51/3 = 17, the weight of the largest, the dog.
Then 24 - 17 = 7, the weight of the cat.
And 10 - 7 = 3, the weight of the rabbit.
So then 17 + 7 + 3 = 27, the total weight of all 3.
Right?