Help me pleased I was not in class because my computer was not working pleased help pleased.

An object weighs 40n in air , weighs 20n when submerged jn water and 30n submerged in a liquid of unknown density .what is the density of the liquid?

Dominic and stacy each have a stamp collection. dominic has six fewer stamps than three times the number of stamps stacy has. dominic and stacy decide to give all of their stamps to their younger sister, mary. if stacy had s stamps, which expression represents the number of stamps that mary received? a. (3s − 18)(3s − 6) b. 2s − 18 c. 4s − 6 d. 4s − 18

What is donald trump wanting to build and have finished by 2020?