Jessie hiked 5 1/2 miles on saturday, 6 3/4 miles on sunday, and 2 1/3 miles on monday. How many miles did jessie hiked altogether?

Which of the following contains a variable?

Tom drove 206 miles in 3.9 hours. estimate his average speed.

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