Given:
To Determine: The probability that a student selected at random will be a sophomore or a mathematics major or both
The probability would be
[tex]\begin{gathered} P(S,or,M,or,\text{both)}=\frac{n(S)+n(M)+n(\text{both)}}{n(\text{total)}} \\ P(S,or,M,or,\text{both)}=\frac{15+5+10}{50} \\ P(S,or,M,or,\text{both)}=\frac{30}{50} \\ P(S,or,M,or,\text{both)}=\frac{3}{5} \end{gathered}[/tex]Hence, the probability of that a student selected at random will be a sophomore or a mathematics major or both is 3/5