Answer:5
Step-by-step explanation:
20 divided by 4 equals 5
Solve the equation of the function for n.
a(n) = 3n - 20
a = 3n - 20
a + 20 = 3n
(a + 20)/3 = n
n = (a + 20)/3
n(a) = (a + 20)/3
There are 5+6+4+3+2=20 m&m's in the bag.
Calculate in how many ways you can choose 3 m&m's from 20:

There are 6 yellow m&m's.
Calculate in how many ways you can choose 3 m&m's from 6:

The probability is the number of ways of choosing 3 m&m's from 6 m&m's divided by the number of ways of choosing 3 m&m's from 20 m&m's.

The probability is 1/57.
You can isolate r to one side of the equation by dividing by adding three, dividing by s, multiplying by a and you get:
r=a(3+k)/s