Question

Alex's dog weights 7 times as much as her cat. together the two pets weigh 72. how much does the dog weigh?

Answer 1

If the dog weighs 7 times more then the cat equals 1 part and the dog weighs 7 parts so together they equal 8 parts 
so you do 72 divided by 8 = 9
then 9x7=63 
the dog weighs 63 units

Answer 2

The dog weigh 504 pounds