Instruction 4 -Referring to Instruction 4

Multiple Choice

Instruction 4.2
An alcohol awareness task force at a large Australian university sampled 200 students after the final exam to ask them whether they went out to a pub on the weekend before the exam or spent the weekend studying, and whether they did well or poorly on the exam. The following result was obtained.
$$\begin{array} { | l | l | l | } \hline & \text { Did Well on Exam } & \text { Did Poorly on Exam } \\\hline \text { Studying for Exam } & 80 & 20 \\\hline \text { Went to a pub } & 30 & 70 \\\hline\end{array}$$
-Referring to Instruction 4.2,what is the probability that a randomly selected student did well on the exam or went to a pub on the weekend before the exam?

A) (80 + 30 + 70) / 200 or 90%
B) 30/200 or 15%
C) (80 + 30) / 200 or 55%
D) (30 + 70) / 200 or 50%