Michael and his friends like to collect pokemon and digimon cards. a total of 18 friends said they collect pokemon cards, and a total of 15 friends collect digimon cards. four of his friends said that they collect both pokemon and digimon cards.
a. draw a venn diagram.
b. what percentage of michael’s friends collect pokemon cards?
c. what percentage of michael’s friends collect digimon cards?
d. are these independent events?
they are separate questions not multiple choice

Nthe opening scene of the movie raiders of the lost ark, indiana jones replaces a golden statue with a bag of sand. the platform on which the statue is placed is designed to detect the mass of the statue. if the bag of sand has a different mass than the statue, then a mechanism triggers and destruction ensues. the density of gold is about 20\text{ g/cm}^320 g/cm 3 20, space, g, slash, c, m, start superscript, 3, end superscript. the density of sand can be estimated at 2.5\text{ g/cm}^32.5 g/cm 3 2, point, 5, space, g, slash, c, m, start superscript, 3, end superscript. the gold statue can be modeled as a cylinder with height 25\text{ cm}25 cm25, space, c, m and radius 8\text{ cm}8 cm8, space, c, m. in terms of \piπpi, what is the mass of sand indiana jones needs to avoid triggering the mechanism?