If i have 1/4 cup of sugar and i need 1 1/3 cups how much more sugar do i need

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Elena and her husband marc both drive to work. elena's car has a current mileage (total distance driven) of 15,000 and she drives 23,000 miles more each year. marc's car has a current mileage of 46,000 and he drives 9,000 miles more each year. will the mileages for the two cars ever be equal? explain.

Which choice represents the sample space ,s for this event