Samuel bought 30 books. the hardcover books cost 20 dollars while the paper back books cost 8 dollars. if the total amount of books costed 480 dollars, how many passer back books were purchased?

Which of the following values have 3 significant figures? check all that apply. a. 10.1 b. 100.05 c. 120 d. 129

An archaeologist in turkey discovers a spear head that contains 53% of its original amount of c-14. find the age of the spear head to the nearest year. (5250 isn’t right)

Carmen and matt are conducting different chemistry experiments in school. in both experiments, each student starts with an initial amount of water in a flask. they combine two chemicals which react to produce more water. carmen's experiment starts with 30 milliliters of water in a flask, and the water increases in volume by 8.5 milliliters per second. matt's experiment starts with 10 milliliters of water and increases in volume by 28% each second.