Kayla began a science project with 18 grams of an unknown solid . During the experiment the change in mass of the solid -7 grams . What was the mass number f the solid at the end of the experiment

Bill works as a waiter and is keeping track of the tips he ears daily. about how much does bill have to earn in tips on sunday if he wants to average $22 a day? tips by day tips (dollars) monday tuesday wednesday thursday friday saturday $14 $22 $28 $36

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.

Xy x xy if a and b are positive integers such that a*b=9 and b*a=72 what is the value of a/b