Pls help my brain is starting to lag

Jenisey has $24 to spend on seven pencils. after buying them she had $10. how much did each pencil cost.?

You have 17 cats that live in houses on your street, 24 dogs, 3 fish, and 4 hamsters. what percent of animals on your block are dogs?

Alarger number is double the sum of a smaller number. the larger number is 2 less than 3 times the smaller number. if y represents the larger number and x represents the smaller number, which equations model the situation