A circle has a diameter of 12 inches. A central angle of the circle intercepts an arc with a length of 3 inches. What is the radian measure of this central angle? A.2
B.4
C.0.25
D.0.5

This is geometry. could anyone ? i can't fail this class. my grade is quite low already.

At the olympic games, many events have several rounds of competition. one of these events is the men's 100-meter backstroke. the upper dot plot shows the times (in seconds) of the top 8 finishers in the final round of the 2012 olympics. the lower dot plot shows the times of the same 8 swimmers, but in the semifinal round. which pieces of information can be gathered from these dot plots? (remember that lower swim times are faster.) choose all answers that apply: a: the swimmers had faster times on average in the final round. b: the times in the final round vary noticeably more than the times in the semifinal round. c: none of the above.

Multiplying fractions by whole number 5 x 1/3=?