Element X decays radioactively with a half life of 13 minutes. If there are 830 grams of Element X, how long, to the nearest tenth of a minute, would it take the element to
decay to 20 grams?
y = a(.5)

5× 1/2 = ? a) more than 5 because you are multiplying by a whole number b) 5/10 because you multiply the numerator and denominator by 5 c) less than 5 because you are multiplying by a number that is more than 1 d) less than 5 because you are multiplying by a number that is less than 1

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

Which shows a reasonable estimation for 124% of 42 using the distributive property?