Answer:
3c
Step-by-step explanation:
[tex]average = \frac{a + b + c}{3} [/tex]
Substitute a= b +2c:
[tex] \frac{a + b + c}{3} = \frac{b + 2c + b + c}{3} \\ \frac{a + b + c}{3} = \frac{2b + 3c}{3} [/tex]
Substitute b= 3c:
[tex] \frac{a + b + c}{3} = \frac{2(3c) + 3c}{3} \\ \frac{a + b + c}{3} = \frac{6c + 3c}{3} \\ \frac{a + b + c}{3} = \frac{9c}{3} \\ \frac{a + b + c}{ 3} = 3c[/tex]
Thus, the average of the 3 numbers is 3c.
