[tex]\begin{gathered} r_1=\text{ Number of student that take neither of the majors=47} \\ r_2=\text{Biology majors only=}12 \\ r_3=\text{Student that take both biology and math=}4 \\ r_4=Math\text{ major only=}7 \end{gathered}[/tex]
a. The number of student surveyed is = 12 + 7 - 4 + 47 = 62
b. The number of student that are math major but not biology major = 7
c. The number of student that are neither math major nor biology major = 47
d. The number of student that are both math and biology major = 4
