The half-life of sodium-22 is 2.6 years. a sample contains 800 mg of this isotope.

Alex drew a circle with right triangle prq inscribed in it, as shown below: the figure shows a circle with points p, q, and r on it forming an inscribed triangle. side pq is a chord through the center and angle r is a right angle. arc qr measures 80 degrees.

Inez has a phone card. the graph shows the number of minutes that remain on her phone card a certain number of days.

Write the pair of fractions as a pair of fractions with a common denominator