in science class vicky did an experiment with an unknown soild. she started with 21 grams of the solid. During the experiment , the change in the mass of the solid was -4 grams. what was the final mass of the solid ?

Sherrie is baking a pie for her family. she leaves the room and comes back to 35% of the pie having been eaten before she can put the topping on. how much 1 square inch strips of dough will she need for the top, now that a portion is missing? round your answer to the nearest while nimber.

Sawsan recorded the favorite sport of students at her school. she surveyed 200 students. how many students chose tennis?

If a=0.333333 and b=0.55555, what is the value of a+b