The half-life of a radioactive kind of antimony is 60 days. If you start with 280 grams of it, how much will be left after 120 days?

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angles. measure need asap

Use the data on the dot plot to answer the question.how many people read for more than three hours last week? i'm on a unit test review

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?