There are twice as many students in the cooking club as in the drama club. Suppose there are $a$ students in the drama club and $b$ students who are members of both clubs. Find an expression for the total number of students who are in the cooking club or the drama club but not both. Give your answer in simplest form.

Total Students = 3a - 2b

Step-by-step explanation:

Given

Students in drama club = a

There are twice as many students in cooking club as in drama club;

So, Students in cooking club = 2a

Members of both clubs = b

Required

Expression for total students in cooking or drama club but not both;

To do this, number of students in individual clubs need to be calculated;

Let Students in drama club only  be represented by D and Students in cooking club only be represented by C

So,

D = Students in drama club - Members of both clubs

D = a - b

Similarly,

C = Students in cooking club - Members of both clubs

C = 2a - b

So, total students in cooking or drama club but not both D + C

Total students = a - b + 2a - b

Collect like terms

Total Students = a + 2a - b - b

Total Students = 3a - 2b