2.8% as a fraction in simplest form

Acircle has a circumference of 28.36 units what is the diameter of the circle

How do i start to solve? would appreciate a walk-thru! a bird sitting 16ft above the ground in an apple tree dislodges an apple. after how many seconds does the apple land on the ground? (assuming that no branches will interfere with it's fall)

Write two point-slope equations for the line passing through the points (6, 5) and (3, 1)