Raphael is twice as old as his sister is. the sum of their ages is less than 30. what is the greatest age raphael’s sister can be? the greatest age raphael's sister can be is 9 years old. the greatest age raphael's sister can be is 11 years old. the greatest age raphael's sister can be is 20 years old. the greatest age raphael's sister can be is 10 years old.

You coordinate volunteers for litter cleanup in local parks. your spreadsheet lists drivers and the number of seat belts in each driver’s car. the spreadsheet calculates the number of drivers (d) and the total number of seat belts (s). you want to know the maximum number of volunteers, besides drivers, that can be transported to the park in a single trip given that each person must have a seat belt of their own.