HELP HELP LAST ONE !

In the diagram of circle o, what is the measure of zabc?

Which of the following pair(s) of circles have las a common external tangent? select all that apply. a and b a and c b and c

Aprobability experiment is conducted in which the sample space of the experiment is s={7,8,9,10,11,12,13,14,15,16,17,18 }, event f={7,8,9,10,11,12}, and event g={11,12,13,14}. assume that each outcome is equally likely. list the outcomes in f or g. find p(f or g) by counting the number of outcomes in f or g. determine p(f or g) using the general addition rule.