Writing Equations from word problems Can you show me how to write the equation and solve it?

2. Old Mcdonald's 3 hens each lay the same number of eggs one week. This gives Old Mcdonald's wife enough eggs to make two recipes. One recipe requires 10 eggs and the other recipe requires 2 eggs. How many eggs did each hen lay? 3. The vet put 2 litters of kittens in a cage with 5 other kittens. She also put 3 litters of puppies in the next cage with 1 other puppy. If all of the litters have the same number of animals and the cages now contain the same number of animals, how many animals are in each litter? 4. Brian buys 1 pack of baseball cards to add to the 2 cards a friend gave him. Then his mother gives him 2 more packs as a special treat. Now he has as many cards as Marcus who owns 1 pack plus 12 loose cards. How many cards are in each pack? 5. Paul owns a set of model cars. His brother gives him 3 more sets for his birthday. Then Paul gives 1 set to a friend who really likes model cars but doesn't have any. Now Paul has 30 model cars left. How many model cars are in each set