13) A certain radioactive isotope decays at a rate of 0.1% annually. Determine the half-life of this isotope, to the nearest year.
C) 301 yr
D) 500 yr
A) 7 yr
B) 693 yr

The circumference of a circle is 5 pi cm. what is the area of the circle?

Which statement about the relative areas of ? abc and ? xyz is true? the area of ? abc > the area of ? xyz the area of ? abc < the area of ? xyz the area of ? abc = the area of ? xyz more information is needed to compare.

896.31 cm= km 100cm = 1m 1000m = 1km a) 0.0089631 b) 0.0089631 c) 8.9631 d) 89.631