A sample of a radioactive isotope had an initial mass of 650 mg in the year 2003 and decays exponentially over time. A measurement in the year 2005 found that the sample's mass had decayed to 490 mg. What would be the expected mass of the sample in the year 2007, to the nearest whole number?

c.35

step-by-step explanation:

8+13=21

21+8=29

29+6=35

54 km / hours

step-by-step explanation:

we need to convert seconds to hours

60 seconds = 1 minutes

60 minutes = 1hour

15 m         60 second   60 minutes

  * *         = 54000 meters/ hour

second     1 minute             1 hour

now we need to convert meters to km

1000 m = 1 km

54000 m       1 km

*   = 54 km / hours

hour               1000m