Kara and John are pushing their grocery carts along a flat surface in a store. Kara's cart is empty, and John's cart is full.Kara and John each push their cart with the same force. Why does Kara's cart speed up more than John's cart when they push with the same force?.

20 dogs

Explanation: The quickest way is to make a fraction of 26/40. 26 divided by 2 is 13 and 40 divided by 2 is 20.

The best way is to set up a proportion: 26 lbs/40 dogs=13 lbs/x dogs.

Cross multiplying (26*x and 13*40) leaves us with 520=26x.

When we divide both sides by 26, we find that 20 dogs is the answer.