It's saying that on every other stop(with even numbers)you add 2 people, and on all the other stops(odd numbers)you subtract 5 people. Be sure that you start with 18 people on the bus! Keep doing this until there is no more people on the bus!
Your sister would be 66. When you are 10, your sister would be 6 (10-4=6) 60 years later, you would be 70, and your sister would still be 4 years younger.
There isn't an obvious question to this problem but with the given we can assume what is to be asked. I think we are to find the total cost of a certain poultry seasoning. The poultry seasoning would have a total weight of 4+2=6 ounces. The total cost will then have to be 4(4) + 2(3) = 22 dollars.
