The average of nine consecutive even numbers is 24. What is the average of the smallest three of these 9 given numbers?

Let's assume nine consecutive even numbers are y, (y+2), (y+4), (y+6), (y+8), (y+10), (y+12), (y+14) and (y+16).

The average of nine consecutive even numbers is 24.

$$\frac{y+(y+2)+(y+4)+(y+6)+(y+8)+(y+10)+(y+12)+(y+14)+(y+16)}{9}\ =\ 24$$

$$y+(y+2)+(y+4)+(y+6)+(y+8)+(y+10)+(y+12)+(y+14)+(y+16)\ =\ 216$$

9y+72 = 216

y+8 = 24

y = 24-8

y = 16

Average of the smallest three of these 9 given numbers = $$\frac{y+(y+2)+(y+4)}{3}$$

= $$\frac{3y+6}{3}$$

= y+2

= 16+2

= 18