Benny bought 4 new baseball trading cards to add to his collection. The next day his dog ate half of his collection. There are now only 24 cards left. How many cards did Benny start with?

The weight of a radioactive isotope was 96 grams at the start of an experiment. after one hour, the weight of the isotope was half of its initial weight. after two hours, the weight of the isotope was half of its weight the previous hour. if this pattern continues, which of the following graphs represents the weight of the radioactive isotope over time? a. graph w b. graph x c. graph y d. graph z