Use the Three-Class Confusion Matrix Below to Answer Questions 1

Short Answer

Use the three-class confusion matrix below to answer questions 1 through 3.
$$\begin{array}{l}\text { Computrd Decision }\\\begin{array} { | c | c | c | c | } \hline & \text { Class 1 } & \text { Class } 2 & \text { Class } 3 \\\hline \text { Class 1 } & 10 & 5 & 3 \\\hline \text { Class } 2 & 5 & 15 & 3 \\\hline \text { Class } 3 & 2 & 2 & 5 \\\hline\end{array}\end{array}$$
-How many class 2 instances are in the dataset?