Three is added to a number, and then the sum is multiplied by 4. the result is 16. find the number

Cynthia takes her dog to the park every 2 days. she bathes her dog every 7 days. if she took her dog to the park and bathed him today, how long will it be until she does both on the same day again?

Can someone me and do the problem plz so i can understand it more better

Paul’s car is 18 feet long. he is making a model of his car that is 1/6 the actual size. what is the length of the model?