4 teachers selected from 13 parents and 5 teachers
To solve this problem, we will use combinations. A combination is a selection of items where order does not matter.
In this problem, we need to select 4 teachers from a group of 13 parents and 5 teachers. Since we only want to select teachers, we will consider the 5 teachers as our main pool of candidates.
To calculate the number of combinations, we will use the formula for combinations:
nCr = n! / (r!(n-r)!)
Where n is the total number of items, and r is the number of items we want to select.
Let's plug in the numbers:
n = 5 (number of teachers)
r = 4 (number of teachers to select)
5C4 = 5! / (4!(5-4)!)
= 5! / (4! * 1!)
= (5 * 4 * 3 * 2 * 1) / (4 * 3 * 2 * 1 * 1)
= 5
So, there are 5 possible combinations to select 4 teachers from 13 parents and 5 teachers.