Which weighs more: a watermelon that weighs 7.5 kilograms or a baby that weighs 12 pounds? Note: 1 pound is about 0.45 kilograms.

Jonathan can type 20 documents in 40 minutes ,and susan can type it in 30 minutes and jack can type it in 24 minutes working together ,how much time will it is take them type the same document

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.

240 seventh graders and two-thirds of the students participate in after-school activities how many students participate in after-school activities