In a survey of a TriDelt chapter with 50 members, 18 were taking mathematics, 37 were taking English, and 7 were taking both. How many were not taking either of these subjects?

50 - (18-7) - (37-7) = ?

To find the number of members who were not taking either mathematics or English, we need to subtract the number of members taking at least one of these subjects from the total number of members in the TriDelt chapter.

First, let's find the number of members taking at least one of the subjects. For this, we can use the principle of inclusion-exclusion.

The total number of members taking mathematics (18) and the total number of members taking English (37) includes those who are taking both subjects. Since we want to count them only once, we need to subtract the number of members taking both subjects.

To find the number of members not taking either subject, we subtract the number of members taking at least one of the subjects from the total number of members in the chapter.

Total number of members = 50
Number of members taking at least one of the subjects = Number of members taking mathematics + Number of members taking English - Number of members taking both

Number of members taking at least one of the subjects = 18 + 37 - 7 = 48

Number of members not taking either mathematics or English = Total number of members - Number of members taking at least one of the subjects

Number of members not taking either mathematics or English = 50 - 48 = 2

Therefore, there were 2 members who were not taking either mathematics or English.