Question

a man and a daughter stand on a scale they weigh 90kg. The man gets back on with his cat together they weigh 70kg. The daughter and the cat weigh 40kg together. How much do the man, his daughter, and their cat weigh on their own?

Answer 1

The man is 60kg and the daughter 30kg  because 60+30=90. The cat has to weigh 10kg because the man's weight 60kg plus the cat's weight 10kg is 70kg. Also because the daughter's weight 30kg plus the cat's weight 10kg is 40kg.

Answer 2

The man weighs 60kg. The daughter weighs 30kg. The cat weighs 10kg.